A young woman pleaded for mercy before being left critically injured by a moped mugger - as new figures showed another shocking rise in violent crime in London.

The 24-year-old victim begged “no,no,no” as she grappled with a teenage thug in the robbery in a residential street in north London on Monday, witnesses said.

She fell to the ground after being hit with a “knockout” punch and was today in hospital in a critical condition.

Police said her mobile phone and bag were stolen in the assault in Holyrood Gardens, Edgware just after 9pm and appealed for witnesses.

The plea came as new Met police figures showed a five per cent rise in violent crime in the 12 months to the end of April this year.

Statistics showed there were 35 youth homicides in the last 12 months, up 25 per cent, a surge in the rate of muggings, up 30 per cent and an 18 per cent rise in knife crime offences.

Other figures also revealed a 50 per cent rise in moped muggings in the last 12 months to a rate of 60 offences a day.

Senior Met chiefs faced questions over the rise in violence at a meeting of the London Assembly police and crime committee today.

Committee chairman Steve O’Connell said: “We continue to see a depressing rise in shocking crimes which leave Londoners vulnerable to the most harmful types of criminality which can leave people scared and a legacy of emotional and physical problems.

“We are determined to find out what is working and what is not in the battle against violence in London.”

Witnesses to the Edgware mugging told how the woman was attacked by a teenager, who had been a passenger on a moped.

One said: “She had her headphones in and she was shouting ‘no, no, no’ at him.

“He managed to grab whatever it was he was pulling at and the moped then mounted the pavement for him to jump back on.

“The driver then grabbed her handbag off her shoulder and again she fought back and was pleading for mercy and was shouting ‘no, no, no’. The passenger shouted, ‘give it up’ and took it. That’s when the passenger decided to punch her face right in. I knew it was a knockout punch.”

The witness added: “I sat on the floor with her trying to keep her awake. She was conscious, she was slurring, she was saying something but I couldn’t understand her.

“She was aware she had head injuries and kept touching the back of her head, to the point where she took a clip out of the back of her head because it was hurting her.”

Detective Sergeant Richard Lewsley said: “This was a horrific attack, the victim had her bag on her shoulder when the males approached her. She resisted for some time until the pillion passenger punched her, causing her to fall backwards.

“She is currently in a critical condition and we need to catch these males before they strike again.”

The mugging took place just hours after comedian Michael McIntyre was robbed of his £15,000 Rolex by hammer-wielding moped thieves outside his son’s school in Golders Green.

In another development a boy aged 14 was charged with the murder of a man in Chelsea last week. The boy appeared in court yesterday in connection with the stabbing of Mark Fontaine of Walthamstow.

Today Scotland Yard arrested 27 people in a series of dawn raids in Tower Hamlets in a crackdown on drugs and violence.

More than 150 officers raided 30 addresses across the borough ands seized £20,000 in cash, two Taser weapons and a quantity of drugs.