Tennis star Naomi Osaka has added her voice to protests over the death of an African American man in U.S. police custody, criticizing people for tweeting more about lootings than his death.

Protests set off by the death of George Floyd, an unarmed 46-year-old who died in Minneapolis after being pinned beneath a white police officer's knee for nearly nine minutes, erupted around the United States again on Monday, the latest of several days of violence.

Osaka, who was born in Japan to a Haitian father and a Japanese mother, had previously passed her time in quarantine posting lighthearted selfies in stylish clothes or by the side of a pool.