Wherever Rihanna goes, trouble often follows, and we're not exactly talking about Chris Brown.

RiRi was partying in London, since she was in town for the debut of her River Island fashion collection during the city's Fashion Week. She hit The Box nightclub and left with a bloodied knee, the result of an altercation.

So what happened?

We're not 100 percent sure, but TMZ reports that someone threw a bottle in her direction and screamed things about Breezy.

That scenario sounds eerily similar to the epic battle bottle in NYC between Brown and Drake last summer. Ri wasn't there, but she was said to be part of the reason their respective crews went nuclear in a club.

Sources say that RiRi was exiting the London club when someone threw a bottle of Lucozade, which is an energy drink, her way. The bottle didn't hit her or make contact, but she did cut her knee when she brushed up against a metal grate and scraped it.

Ouch. We hope that doesn't leave a scar, since Ri has great stems.

What's with people throwing bottles at clubs? That's dangerous business, especially since innocent bystanders can get caught in the crosstoss.

As for ChRihanna, the couple is reportedly on the outs… again. This is reportedly the reason why.

Watch the Rihanna 'Stay' Video