This is the moment a woman tried to stab a 15-year-old boy with a kitchen knife as he boarded a bus with his grandmother.

Police said the 51-year-old defended her grandson when he was approached by the woman on a route 133 bus on Brixton Road, in south London.

The suspect, who was already on the bus, attacked the boy before his grandmother intervened.

The woman, wearing a distinctive headscarf with a kangaroo print, attempts to stab the boy with a large kitchen knife as he stands on the bus

She managed to disarm the suspect, who then got off the bus and fled north towards Oval.

The boy suffered a minor cut to the stomach, the Metropolitan Police said, and the eight-inch knife was later recovered. Police said they were investigating the incident as an 'attempted stabbing' as the injury was a slash rather than a puncture wound.

Police have released CCTV footage of a woman who tried to stab a 15-year-old boy with a kitchen knife as he boarded as bus with his grandmother

Officers have today released CCTV footage as they hunt for the suspect.

A Met Police spokesman said: 'On 26 December 2015 at about 12:30hrs, the 15-year-old boy boarded a Route 133 bus on Brixton Road with his 51-year-old grandmother.

'The suspect, who was already on the bus, approached the victim and produced a large kitchen knife, which she attempted to stab the victim with.

'The victim's grandmother intervened and managed to disarm the suspect, who then got off the bus and fled towards Oval.'

The suspect is described as an Asian woman, aged about 20 to 30 years.

She wore a distinctive headscarf with a kangaroo print.

Anyone who was on the bus at the time of the incident or has any information, is urged to call police via 101 or Crimestoppers anonymously on 0800 555 111 quoting reference 199092.

CCTV footage released by Scotland Yard captures the moment the woman and 15-year-old were on the bus on Brixton Road, in London

The teenager suffered a cut to his stomach during the attack at around 12.30 Boxing Day last year