Rihanna celebrated the London premiere of her River Island collection before being attacked by a male fan. Tumblr

Rihanna ended up with a bloody knee during London Fashion Week, after a fan allegedly assaulted the singer over her rekindled romance with Chris Brown.

The “Diamonds” artist was in the country to debut her latest clothing line with British fashion line River Island. She later celebrated with her entourage, which included best friend Melissa Forde and model Cara Delevingne, at the Box Nightclub.

Around 3 a.m. on Sunday, an angry male fan yelled insults at Rihanna regarding Brown, and screamed at her for being with the singer, the New York Daily News said.

Witnesses reported that he threw a bottle at her, causing Rihanna to fall against a metal grate and cut her right knee.

Rihanna and her entourage then immediately left the scene. Her bodyguard was also injured during the scuffle and had to be treated at a nearby hospital.

The enraged fan is not the only one who is not pleased that Rihanna has gone back to Brown, who physically assaulted her in 2009.

Rihanna’s former best friend, Katy Perry, has also been avoiding the singer. They were not spotted near one another at the 55th Grammy Awards earlier this month, as Rihanna chose instead to cozy up to Brown.

The Daily Mail reported that Perry even specifically asked not to be seated near the couple, who sat in the front row by the stage.

“They aren't tight anymore because Katy doesn't approve of Rihanna dating Chris Brown,” a source told USMagazine.

Yet, Rihanna has made no secret about her love for Brown, though he gave her a black eye and a swollen lip after a heated argument just three years ago.

"My stomach drops and I have to maintain this poker face and not let it get to the outer part of me,” Rihanna explained to Oprah last year about how she feels when she sees Brown.

"We love each other and we probably always will."