The NBA postponed Wednesday's three play-off games after the Milwaukee Bucks boycotted their fixture in protest at the shooting of Jacob Blake.
The incident took place in Kenosha, Wisconsin, 40 miles from Milwaukee.
The Bucks' senior vice president, Alex Lasry, tweeted: "Some things are bigger than basketball. The stand taken today by the players and organisation shows that we're fed up. Enough is enough."
He added: "Change needs to happen. I'm incredibly proud of our guys and we stand 100% behind our players ready to assist and bring about real change."
The Bucks were due to play the Orlando Magic. After the postponement, a statement on behalf of the Magic and their owners, the DeVos family, read: "Today we stand united with the NBA office, the National Basketball Players Association, the Milwaukee Bucks and the rest of the league condemning bigotry, racial injustice and the unwarranted use of violence by police against people of colour."
The Houston Rockets' game against the Oklahoma City Thunder and the Los Angeles Lakers' match-up with the Portland Trail Blazers were also postponed, and will be rescheduled.
The Lakers' LeBron James tweeted: "We demand change. Sick of it."
Prior to the scheduled game, Bucks coach Mike Budenholzer said: "Myself, my players and our organisation are very disturbed by what happened in Kenosha.
"It is a great challenge to have an appreciation and a desire to want change, to want something different and better in Kenosha, Milwaukee and Wisconsin, and then to go out and play a game."
The Athletic reported that NBA players are scheduled for a meeting in Florida later on Wednesday to determine their next steps, with NBA TV saying that some players are contemplating leaving the NBA bubble near Orlando.
Earlier on Wednesday, NFL's Detroit Lions cancelled their practice session. Players then gathered in front of the team facility, holding signs which read: "We Won't be Silent" and "The World Can't Go On."
After the NBA boycott, the NHL are expected to hold a 'moment of reflection' before the games between the Boston Bruins and Tampa Bay Lightning in Toronto, and the Dallas Star and Colorado Avalanche in Edmonton.
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