Amy Winehouse arrested!

The "Rehab" singer headbutted a man who was trying to hail her a taxi, and punched a second man in the face.

Winehouse was also seen walking into a lamp post, making out with a random man in the bar who was most decidedly not her incarcerated husband Blake Fielder-Civil, overturning tables and drinks, and stiffed her cabbie for half his fare on her way home.

Amy swung at Moroccan musician Mustapha el Mounmi when he wouldn't move away from the pool table fast enough, leaving him with a black eye and a swollen lip.

"I feel so angry," he said. "She smashed my face hard. I could not hit back -- she's a woman."

As is Scotland Yard's policy, the police agency did not specifically name Amy, but said...

"A 24-year-old woman has been arrested on suspicion of assault after attending a central London police station by appointment. She is currently in custody. The doctor has seen the 24-year old woman and has said that she is not fit to be interviewed. That means that we cannot deal with her for at least four hours and until the doctor has seen her again."

Amy was seen entering the police station two hours late for her scheduled interview. If convicted, she faces three years in jail.