Amy Winehouse arrested in London on suspicion of assault

British singer Amy Winehouse has been arrested in London on suspicion of assault.

She voluntarily reported to a London police station on Friday to answer questions, and was detained.

"A 24-year-old woman has been arrested on suspicion of assault after attending a central London police station by appointment," a Scotland Yard spokesman told the BBC. "She is currently in custody."

The troubled star earlier this week allegedly headbutted an onlooker who attempted to help her get a taxi, because she thought he was trying to molest her.

She also was alleged to have punched a second person in the face.

One of the men Amy is accused of attacking, Mustapha el Mounmi, 27, said, "I feel so angry. She smashed my face hard. I could not hit back -- she's a woman,"

The singer -- worth an estimated $20m, according to the Sunday Times Rich List -- failed to turn up and support her husband, Blake Fielder-Civil, for a court appearance today.