Naomi Osaka pulled out of the semi-finals of the Western & Southern Open tennis tournament on Wednesday in protest at racial injustice.

Osaka, who has a Japanese mother and Haitian father and has been a vocal supporter of the ‘Black Lives Matter’ movement, said in a social media post: “Before I am an athlete, I am a Black woman”.

Her decision follows protests over the police shooting of Jacob Blake, a Black man, in the city of Kenosha, Wisconsin, on Sunday.

Earlier on Wednesday, the National Basketball Association postponed three playoff games after the Milwaukee Bucks boycotted Game 5 of their playoff series against Orlando Magic in protest over racial injustice.

In Osaka`s statement, posted on Twitter, she said she was making the decision to move the conversation forward.

“As a Black woman I feel as though there are much more important matters at hand that need immediate attention, rather than watching me play tennis,” the world number 10 wrote.

“I don`t expect anything drastic to happen with me not playing, but if I can get a conversation started in a majority white sport I consider that a step in the right direction.

“Watching the continued genocide of Black people at the hand of the police is honestly making me sick to my stomach.”

Osaka beat Anett Kontaveit 4-6, 6-2,7-5 on Wednesday to reach the semi-finals, where the two-time Grand Slam champion was due to face Elise Mertens.