Peter Kopwalczyk, of south London, has been charged with common assault and “sectioned under the Mental Health Act,” Scotland Yard told the BBC.

Kopwalcyzy is accused of punching Lewis in the head yesterday during a signing session for her autobiography “Dreams.”

A fan on the scene at the Waterstone’s book store in London’s Picadilly district described the attack to the BBC, saying, “My brother saw the whole incident. [Kopwalcyzy] walked up there with the book, she signed it and, as she looked up, he just punched her.”

Another fan described the aftermath, telling the BBC, “[Lewis] was running out with her hand over her eye and I just saw a man on the floor.

“Suddenly the security all jumped on him and they were trying to pull him out and he was just laughing, he thought it was funny.”

The singer canceled a planned publicity visit to Germany today and issued a statement saying she was “extremely hurt and upset” and that the experience had been “truly overwhelming.” She also thanked fans for their support and apologized for being forced to disappoint some of them.

“I’m very sorry to those I wasn’t able to meet at the signing,” Lewis said. “Thank you again for all of the lovely messages. Love you all.”

Lewis, who landed three Grammy Award nominations for her debut album, will release the follow up, Echo, next month.