A man has been charged and sectioned under the Mental Health Act, after Leona Lewis was punched during a book signing in London.

Peter Kopwalczyk, 29, from south London, was arrested at the Waterstone's book store in central London on Wednesday afternoon moments after the Bleeding Love singer was assaulted as she signed copies of her autobiography for fans.

Police say Kowalczyk has been sent to a mental hospital, but is due to appear in court charged with assaulting the former X Factor winner later this month.

A Scotland Yard spokesman said: 'Peter Kowalczyk, aged 29 of SE1, has today been charged with common assault and sectioned under the Mental Health Act. He is due to appear at city of Westminster Magistrates Court on October 26th.'

Leona cancelled a visit to Germany today as she recovered from the assault.

The 24-year-old had been due to fly out for a day-long promotional trip, but pulled out in the aftermath of the incident.

Former X Factor winner Lewis had been signing copies of her autobiography at Waterstone's Piccadilly in London yesterday afternoon, when a man in the queue allegedly lashed out. She was left 'shaken'.

Lewis said today that the experience was a 'horrible shock'.

In a statement she said: 'Thank you so much for your support, it is truly overwhelming.

'Yesterday was a horrible shock and left me extremely hurt and upset. I'm very sorry to those I wasn't able to meet at the signing.

'Thank you again for all of the lovely messages. Love you all.'

Her spokesman said: 'Leona was due to go to Germany today for promo but that has now been cancelled.'

He added: 'Leona is obviously shocked after yesterday but is OK.'

Shocked fans could only look on in horror as she clutched her head before bursting into tears.

Five security guards piled in to restrain her attacker, pinning him to the ground until police arrived at the scene.

One fan told the BBC: 'My brother saw the whole incident.

'He [the attacker] walked up there with the book, she signed it and, as she looked up, he just punched her.'

Another witness said her attacker yelled: 'I love you, Leona' - and she screamed back: 'I don't love you.'

A separate bystander added: 'I heard Leona cry out in pain and she was quickly led off by her security as more security guards and fans restrained the man until police arrived.

'She had sunglasses on and even though she had her face in her hands you could see she was clearly crying and her face was swollen.

'The worst thing is that the man was grinning - he thought it was funny.'

The man is described as over 6ft, skinny, with mousy brown long hair. He was wearing scruffy jeans and a jacket.

A spokesman for Miss Lewis, who witnessed the attack, said he did not hear the man say anything.

He confirmed the singer had suffered bruising to the side of her head and was taken to a private doctor in Central London as a precaution.

Waterstones said it took security at book signings "extremely seriously" and this was the first incident of its kind.

The firm added: 'We would like to thank Leona for her professionalism and we are extremely sad that this event was ruined for her, and her fans, many of whom queued from the early hours of the morning to meet her.'

The spokesman added that Miss Lewis was left feeling 'shaken', adding: 'Leona is absolutely gutted that she did not get the signings finished.

'This guy whacked her one in the face, and she was sitting down and he was standing up, so you couldn't get more cowardly.

'She was in pain and when police arrived, they advised her to go and see a doctor.

'Leona is incredibly shaken up. It was absolutely horrible.

'She will see how she is feeling today and will decide if she's up to working.

'At the moment, she's too shaken up to think about any of that.

'She is expected to fly to France this weekend but that remains to be seen.'