Cameroon captain Vincent Aboubakar led from the front with a clinical double as the Africa Cup of Nations hosts swept to a 4-1 win over Ethiopia.

At the Olembe Stadium in Yaounde, Aboubakar and Karl Toko Ekambi feasted on generous defending to make it two wins from two for Cameroon. For Aboubakar, this was his second double in AFCON so far, after also scoring twice in an opening win over Burkina Faso.

Ethiopia stunned the home crowd with a fourth-minute opener, Dawa Hotessa tucking in from close range after some dismal defending. But there was a near-immediate response, Cameroon levelling with a fine header from Toko Ekambi in the eighth minute.

Aboubakar saw a 25-yard shot repelled by Ethiopia goalkeeper Teklemariam Shanko in the lead-up, but Collins Fai collected the loose ball wide on the right and sent in a fine cross for Toko Ekambi to finish clinically at the far post.

It was another cross from Fai that caused chaos in the Ethiopia penalty area and allowed the hosts to edge 2-1 ahead in the 53rd minute. The delivery came from the right once more, and Aboubakar powered his header down into the ground and into the back of the net.

Aboubakar's second arrived two minutes later, the striker tucking in Nicolas Moumi Ngamaleu's low cross from the edge of the six-yard box. Toko Ekambi, who also hit the post with a header, completed his own double with a powerful low shot in the 67th minute as Ethiopia's defence stood off, unable to handle Cameroon's quality once more, the story of the game encapsulated.

Africa Cup of Nations hosts Cameroon are back in action as the second matches of the group stage get under way.

Thursday sees Group A take centre stage, with Cameroon facing Ethiopia and Cape Verde taking on Burkina Faso.

Cameroon, champions in 2017, of course have the aim of going all the way on home soil to claim their sixth AFCON title. A win, combined with victory for Cape Verde, would see both progress to the knockout stage with a game to spare.

Cameroon v Ethiopia (16:00 GMT)

Cameroon are ranked 50th in the world by FIFA, making them the seventh-best side in the competition, but tournament hosts always have that extra impetus to go all the way.

Captain Vincent Aboubakar scored both of Cameroon's goals in a 2-1 win over Burkina Faso in their opening match, and victory over Ethiopia – who the Indomitable Lions beat 3-2 in their only previous AFCON encounter in 1970 – will take them through.

Ethiopia are looking to bounce back from their 1-0 loss to Cape Verde. They are winless in their last nine AFCON matches (D3 L6), the longest current such run among teams in this year's competition.

Cameroon, meanwhile, are unbeaten in their previous seven group stage games (W3 D4), last losing in January 2015 (0-1 against Ivory Coast). The five-time champions are aiming to win their opening two games at an AFCON for the first time since 2006. 

One to watch: Vincent Aboubakar

Former Porto forward Aboubakar was Cameroon's Mr Reliable with two penalties in their comeback win over Burkina Faso. Having now scored in his last two AFCON appearances, he will become the first player to net in three consecutive games in the tournament for the Indomitable Lions since Samuel Eto'o in January 2008 (five in total) if he scores on Thursday.

Cape Verde v Burkina Faso (19:00 GMT)

While most of the attention will be on Cameroon, Cape Verde can also book their passage on Thursday.

Cape Verde saw off Ethiopia thanks to Julio Tavares' first-half goal, while Burkina Faso were downed by Aboubakar's two penalties in the space of eight minutes.

This will be the first AFCON encounter between the nations, with Cape Verde looking to remain unbeaten in their opening two games for the third straight tournament, having also done so in their two previous participations (two draws in both 2013 and 2015).

Burkina Faso, meanwhile, are looking to avoid suffering consecutive defeats in a single edition of the tournament since 2012, when they lost all three group matches.

With four of the best-ranked third-placed teams progressing to the knockout stage, Burkina Faso will surely go all out for victory to put themselves firmly in contention despite their opening defeat to Cameroon.

One to watch: Gustavo Sangare (Burkina Faso)

Sangare marked his AFCON debut with the opener against Cameroon and was a standout performer, creating a game-leading four chances. No Burkina Faso player has scored in successive AFCON matches since Alain Sibiri Traore in January 2013.

Vincent Aboubakar scored two penalties as Cameroon came from behind to beat Burkina Faso 2-1 in the opening match of the delayed 2021 Africa Cup of Nations.

After twice being moved due to climate issues and COVID-19, the tournament finally got under way at Olembe Stadum in Yaounde on Sunday.

Burkina Faso took the lead in the first game in Group A, which also includes Ethiopia and Cape Verde, thanks to Gustavo Sangare's back-post volley after 24 minutes.

Bertrand Traore had a header cleared off the line in the build-up to that opening goal, but he gave away a penalty for a trip on Andre-Frank Zambo Anguissa at the other end.

Aboubakar converted following a long VAR review and the Cameroon captain was on target again from the spot eight minutes later after Issoufou Dayo slid in on Nouhou Tolo to concede another penalty.

VAR intervened to deny an offside Aboubakar when he thought he had bundled in a third in the second half, but two goals proved enough for Cameroon to get off to a winning start.

After delays, postponements and date changes aplenty, the Africa Cup of Nations will finally start on Sunday, as hosts Cameroon take on Burkina Faso.

Group A will also pit Ethiopia and Cape Verde against each other on the opening day, with both eyeing up the possibility of staking their claim for a qualification spot behind favourites Cameroon.

But, as may have been expected of a tournament that has had more than its fair share of issues in the build-up, another problem has reared its head on the eve of the big kick-off.

Cameroon v Burkina Faso (16:00 GMT)

Burkina Faso are questioning the validity of the COVID-19 testing that was done on their squad, with "four or five" players and head coach Kamou Malo returning positive results.

They claim an unknown medical team turned up at their hotel to test the team and staff, but they refused to take them after the African Football Confederation (CAF) confirmed the people who had showed up were not sent by tournament organisers.

When the CAF delegation did show up, four positive tests came back and one was inconclusive, with Burkina Faso now demanding new swabs be taken.

Captain Bertrand Traore told reporters: "It's a scandal, we cannot be deprived of first-team players 24 hours before the match.

"The authorities must review the organisation. We cannot accept this decision. We can redo tests of our positive players."

Either way, Cameroon know the pressure is on for them to claim a sixth AFCON title, with this their first tournament as hosts in 50 years.

One to watch: Andre-Frank Zambo Anguissa (Cameroon)

AFCON has never been short of flair players, and in Zambo Anguissa Cameroon have a player really capable of getting fans off their feet. The Napoli man is a fascinating midfielder to watch due to his ability running with the ball. In Serie A this season, his 65.9 per cent dribble success is bettered by only seven midfielders (min. 25 dribble attempts, 500 minutes played), playing an important role in getting the Partenopei out of tight situations and onto the front foot.

Ethiopia v Cape Verde (19:00 GMT)

Four of the six teams to finish third in their group will go through to the next stage, so while that takes away some of the jeopardy for the best teams, it also provides more of a chance for those nations who would not otherwise expect to get far.

With Ethiopia and Cape Verde avoiding Cameroon on matchday one, both will fancy their chances of getting off to a positive start – and three points could be all they need to qualify as one of the best third-placed teams.

Cape Verde have been impacted by a COVID-19 outbreak, though, with coach Roberto Lopes among those infected.

Ethiopia are seemingly in better shape, with coach Wubetu Abate keen to show off their gifted young players.

"We respect our opponents, but we are confident in our talent," he said. "Our goal is not to just participate, but to show the world that Ethiopia has young talented players who can surprise."

One to watch: Amanuel Gebremichael (Ethiopia)

Ethiopia lost talisman – and one of just two foreign-based players – Shimelis Bekele to injury, meaning they will need others to step up. Most of the goalscoring burden is on the shoulders of Getaneh Kebede, but Gebremichael has a skillset that should make him a threat, boasting plenty of speed and the ability to get in behind defences.

Tournament organisers and the Cameroon government on Thursday stated the Africa Cup of Nations "must take place" as they revealed only fans who are fully vaccinated can enter stadiums.

There have been increasing concerns the competition may be called off due to the emergence of the Omicron strain of COVID-19.

The tournament was due to be staged in January and February this year but was postponed due to the pandemic.

Just over three weeks before the opening ceremony at the Complexe Sportif d'Olembe, the government, Confederation of African Football (CAF) and Cameroonian Football Association (FECAFOOT) released a statement vowing that the rearranged AFCON 2021 will go ahead.

The statement said: "In Cameroon, as has been the case elsewhere, effective and reliable measures have been taken as part of a coherent and tried-and-tested approach to counter the pandemic.

"The government has set up a special health protocol to combat COVID-19 that applies to the AFCON.

"In less than 25 days, the best 24 African football teams will participate in the AFCON 2021 and special measures must be taken in connection with this important and prestigious event.

"As is widely known, organised football plays an important role in fostering integration and peace, as well as bringing people together.

"It is also a catalyst of hope, a vehicle for shared values and a conduit for joie de vivre, making it possible to transcend difficulties and see beyond our differences. Therefore, despite the additional challenge posed by the pandemic, the AFCON must take place."

The statement also made clear that supporters will not be allowed into venues unless they are fully vaccinated, while they must also show a negative PCR test result that is no older than 72 hours or a negative antigen test result no older than 24 hours.

CAF will use an independent, internationally recognised laboratory to test players and their delegations.

Holders Algeria have been grouped alongside two-time winners Ivory Coast following the 2021 Africa Cup of Nations draw ceremony held in Yaounde on Tuesday.

The delayed event, which will be hosted in Cameroon from January 9 to February 6, features 24 teams for the second time with six groups of four.

Algeria, who triumphed in Egypt in 2019, are alongside 1992 and 2015 winners Ivory Coast as well as Sierra Leone and Equatorial Guinea in Group E.

Hosts Cameroon will open the tournament in Group A, where they were drawn alongside Burkina Faso, Ethiopia and Cape Verde.

Record seven-time winners Egypt, who last lifted the title in 2010, are grouped with three-time champions Nigeria, Sudan and Guinea-Bissau in Group D.

Arsenal team-mates Pierre-Emerick Aubameyang and Thomas Partey will face off in Group C with Gabon and Ghana alongside first-timers Comoros and top seeds Morocco.

Debutants Gambia are alongside Tunisia, Mali and Mauritania in Group F, while 2019 runners-up Senegal are in Group B with Zimbabwe, Guinea and Malawi.

Africa Cup of Nations draw:

Group A: Cameroon, Burkina Faso, Ethiopia, Cape Verde

Group B: Senegal, Zimbabwe, Guinea, Malawi

Group C: Morocco, Ghana, Comoros, Gabon

Group D: Nigeria, Egypt, Sudan, Guinea-Bissau

Group E: Algeria, Sierra Leone, Equatorial Guinea, Ivory Coast

Group F: Tunisia, Mali, Mauritania, Gambia

Ajax goalkeeper Andre Onana has been suspended for 12 months by UEFA due to a doping violation, the Eredivisie club have confirmed.

Ajax and Onana will appeal to the Court of Arbitration for Sport (CAS) to overturn the ban, imposed after an out-of-competition test in October 2020 found the substance Furosemide in the player's urine.

The club said the test result was due to Onana, 24, mistakenly taking Lasimac – a drug prescribed to his wife – when he felt unwell.

UEFA therefore accepted Onana "had no intention of cheating", an Ajax statement read.

It added: "However, UEFA believes, on the basis of the applicable anti-doping rules, that an athlete has a duty at all times to ensure that no banned substances enter the body."

The suspension is effective from Friday and applies to "all football activities, both national and international".

Ajax managing director Edwin van der Sar said: "We explicitly renounce performance-enhancing drugs, we obviously stand for a clean sport.

"This is a terrible setback, for Andre himself but certainly also for us as a club. Andre is a top goalkeeper, who has proven his worth for Ajax for years and is very popular with the fans.

"We had hoped for a conditional suspension or for a suspension much shorter than these 12 months, because it was arguably not intended to strengthen his body and thus improve his performance."

Cameroon international Onana has been a key man for Ajax since his debut in 2016-17, playing his part in runs to the Europa League final and Champions League semi-finals.

His absence is the latest blow to Ajax, who earlier confirmed they would be unable to correct the administrative error that saw Sebastian Haller left out of their Europa League squad.

Haller, signed from West Ham for a club-record €22.5million last month, was not included in Ajax's initial list for European competition for the second half of the season.

Coach Erik ten Haag described the mistake as "an administrative error with major consequences" and "an incredible setback" for the player, although he confirmed Ajax would be addressing the matter with UEFA.

However, a further club statement has now confirmed UEFA sent "a final message" to say Haller could not be added to the group.

Haller has scored two goals in his first seven games for Ajax in all competitions.