A heavily pregnant woman lost her baby after two men in motorcycle helmets shoved her to the ground and repeatedly stamped on her stomach in an horrific attack.

Police said the 21-year-old victim was set upon by the pair in Peckham on Monday evening, when she was 32-weeks pregnant.

She has been named in reports as Bedfordshire University graduate Malorie Bantala, and remains in a critical condition in hospital.

The attackers - both of whom wore crash helmets - had approached her as she walked in Talfourd Place, where they shoved her over and "continually kicked and stamped on her stomach", according to detectives.

The pair then fled towards Denmark Road after th attack at around 8pm as a bystander called police and administered first aid to the victim.

But the woman tragically lost her baby after being taken to a south London hospital, where she remains in intensive care.

Police said a 20-year-old man has been arrested in connection with the assault, which is believed to have been carried out by two black men in their 20s.

Investigating officer Detective Chief Inspector Robert Pack, from the Met's Homicide and Major Crime Command, said: "This was a truly abhorrent and vile attack on a heavily pregnant woman who has now, tragically, lost her baby.

"The men who attacked her must have known the impact their actions would have when they kicked her repeatedly in the stomach. It is sickening to think someone would deliberately target a pregnant woman in this way.

"The suspects were distinctive in their crash helmets and we would appeal for anyone who saw them either before the attack or running from the scene to please come forward and contact us."

Mr Pack said the woman, who is also black, had managed to provide an account of the attack to officers.

"From what we know at the moment, the working hypothesis is that it was targeted at that unborn child," he said.

"There doesn't appear to be any blows or physical force directed to her head or face. It seems to be all the violence was targeted towards the child."

He added: "There's absolutely no suggestion this is part of a pattern or spate of similar attacks. This is a one-off."

Asked whether the victim knew her attackers, Mr Pack replied: "Quite possibly."

Mr Pack told reporters that murder detectives were dealing with the case because of the "devastating impact" on the woman's life and the "sheer level of mercilessness involved".

A motorcycle has not been recovered by police and it was possible the attackers were wearing helmets as a disguise, he said.

Mr Pack added: "I have absolutely no doubt that someone out there has either heard something, or overheard something, or had someone confide in them.

"It's that sort of person that really needs to search their conscience and think 'This is not on, this is beyond the pale'."

Anyone with information is asked to call police on 020 8345 3985 or contact Crimestoppers anonymously on 0800 555 111.