Boston Celtics head coach Brad Stevens said he wrote a letter of support to his players amid widespread protests and condemnation following the death of George Floyd.

Floyd – an African-American man – died in Minneapolis after a police officer was filmed kneeling on his neck during an arrest last week.

Violent protests have broken out across the United States since Floyd's death, during which he was filmed crying out for help as he was handcuffed and pinned to the ground.

"I wrote a letter to our guys this weekend and it took me a while to put down exactly what I wanted to say," Stevens told reporters in a video conference call on Tuesday.

"But I think the thing I wanted them to know, is every decent person is hurting. Every decent person feels the pain of the African-American community. But I also don't want to pretend that I know the exact, distinct pain.

"What I wanted them to know is that I'm with them. I thought that was really important. It's so, so great to see so many of the guys so active ... I've talked to a lot of guys. Everybody's hurting. Let's put it that way.

"The leadership they've shown is terrific. And hopefully the most important thing is we can have short-term healing, and we can have near-term gains, and we can have long-term sustainable action that creates change."

Celtics star Jaylen Brown led a peaceful protest in Atlanta last week after driving 15 hours from Boston to his home state of Georgia following Floyd's death.

Brown, who streamed part of the protest live via his Instagram account, marched with a megaphone while holding a sign that said, "I Can't Breathe", a reference to Floyd.

"Jaylen's greatest impact, as good as he is in basketball, won't be in basketball. He's a special guy," Stevens said. "He's a special leader. He's smart, but he has courage. He's got a lot of great stuff to him. I think we recognised that when we drafted him, but he has been even more unbelievable every day, every year.

"I've always personally really enjoyed listening to him and talking to him about things outside of basketball. He told me he was going down there on Thursday and I obviously knew ... I'm certainly not surprised by him taking a leadership role. That's who he is."