Kelly Osbourne left a U.K. columnist fuming after she allegedly slapped her in the face - and warned her to "watch it" if she wrote about the incident afterwards.

Osbourne reportedly confronted Sunday Mirror journalist Zoe Griffin on Thursday at London nightclub Punk over an article in which she had alleged model Luke Worrall, Osbourne's boyfriend, had once asked friends how an earthquake is caused.

Griffin writes, "She (Kelly) shouted loudly in my ear: 'I have an issue with you. My boyfriend knows what an earthquake is and everyone has been laughing at him and he's upset.'"

"(Then) I felt a hard slap to my right cheekbone. I put my hand to my face while my friends looked on aghast."

"Soon Kelly came rampaging back over with a female friend jabbing a finger in the air, telling me that I'd have to watch my back if I shared my story with readers of this column."

Griffin adds: "Well sorry Kelly, I won't be silenced by bullies."