A pregnant woman is fighting for her life after she was attacked by two men.
Malorie Bantala, 21, is fighting for her life after she was shoved to the ground by two men in motorcycle helmets who repeatedly stamped on her stomach.
She was 8 months pregnant at the time of the attack in Peckham on Monday evening.
Police were eventually forced to take her to hospital themselves when the ambulance had still not attended the scene more than an hour after being called just after 8pm.
The London Ambulance Service has since apologised for the error as police revealed they believe the violence was "targeted towards the unborn child".
The attackers - both of whom wore crash helmets - had approached her as she walked in Talfourd Place, where they shoved the Bedfordshire University graduate over and "continually kicked and stamped on her stomach", according to detectives.
The pair then fled towards Denmark Road after the attack at around 8pm as a bystander called police and administered first aid to the victim.
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.
Deputy Chief Inspector Pack said:
"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.
From what we know at the moment, the working hypothesis is that it was targeted at that unborn child.
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.
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, Pack replied: "Quite possibly."
He added 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.
"I have absolutely no doubt that someone out there has either heard something, or overheard something, or had someone confide in them," he said.
"It's that sort of person that really needs to search their conscience and think 'This is not on, this is beyond the pale'."
A spokeswoman for the London Ambulance Service said: "We were called at 8.16pm on 15 June to Talfourd Place, SE15.
"We are very sorry that we were unable to send an ambulance before we were cancelled by the police at 9.25pm and are now looking into the circumstances of what happened."
She confirmed that the LAS did not attend and that police officers took the woman to a South London Hospital.