EXTRA police are on patrol in Tottenham after a schoolboy was stabbed to death and three friends injured in a random attack by a "mentally ill man" on Thursday.

Kasey Gordon, 15, of Haringey, who has now been formally identified, died from extreme blood loss after being stabbed in the chest, in West Green Road, as he made his way home from school at 3.45pm.

The Park View Academy pupil, described by his headteacher Alex Atherton as "talented and popular", was allegedly attacked by a man believed to be a mental health patient at nearby St Ann's Hospital, according to community sources.

Eyewitnesses said his attacker, described as a big Turkish man, had been pestering schoolgirls at the end of the school day.

A fight erupted outside a chicken shop with punches being thrown after which the suspect is alleged to have pulled out a weapon to harm the schoolboy. His friends, who were all treated for stab wounds, jumped in to protect him.

Describing the alleged attacker, former Park View pupil David Vanlangenaeker, 18, said: "He is always chasing schoolgirls about.

"He would try and chat to them. He is a big man - about 6ft. He is very scruffy, has long black, curly hair. He is always wearing ripped jeans and Reeboks. He talks like a kid. He talks so crazy."

Acting Borough Commander Chris Barclay, of Haringey police, said: "Every case of violent crime is treated extremely seriously and we are doing everything we can to support the investigation being carried out by our colleagues in the Homicide and Serious Crime Command.

"My officers are carrying out additional patrols to reassure the community."

Detectives from the murder squad said they were "keeping an open mind" about the circumstances of the incident but ruled out it being a targeted attack.

DI Shelia Stewart, of the Homicide and Serious Crime Command, said: "At this time it is unclear how this tragic incident happened. We are appealing for witnesses or anyone with information to come forward.

"It happened on a busy Road in the afternoon, we are speaking to witnesses but would like more people to come forward, no matter how insignificant they think their information is."

Anyone with information is asked to call the incident room on 020 8358 0400 or, to remain anonymous, contact Crimestoppers on 0800 555 111.

A 33-year-old man arrested in a cafe near the scene remains in custody at a north London police station.