A woman has died after being stabbed in the neck in the street in Tottenham, north London.

The victim, who was 42, was attacked in Bruce Grove just before 1pm on Wednesday by a man who witnesses said rolled a cigarette as he waited for police to arrive.

Paramedics were called and the woman was taken to hospital but was pronounced dead, Scotland Yard said.

Sergio Fernandes, 21, who works nearby at Unity Radio Online, said witnesses told him the woman knew her attacker.

"They just said that these people had a history and that the man came and stabbed her four times in the neck. He stood there rolling a cigarette while they were waiting to take her away."

Fernandes, who arrived at the scene after police and paramedics, said he had been told that the woman had just dropped her child off at school.

A murder investigation has been launched and a 46-year-old man who was arrested at the scene is being questioned at a police station in north London.

Scotland Yard said officers knew who the victim was and had told her family but formal identification had yet to take place.

Detective Chief Inspector Noel McHugh said: "I need to hear from anyone who was in the Bruce Grove area shortly before 1pm and who may have witnessed the incident.

"Anyone with information should call the incident room on 020-8785 8099. To remain anonymous call Crimestoppers on 0800-555 111."