Scotland Yard officers were urgently hunting a crazed knife-man who stabbed four complete strangers in the space of a few hours after approaching them at random.

A 45-year-old woman and a 23-year-old man remained in a critical condition in hospital and two others were seriously hurt following what detectives described as a series of "senseless and cowardly" attacks.

Officers flooded the streets of Edmonton in north London and warned the public to be vigilant following the spate of linked knifings which occurred in the space of just over 12-hours.

The attacker was described as a black man, approximately 6ft 3ins tall, of skinny build and wearing dark clothing, possibly a hooded top.

The incidents followed another upsurge of bloody violence across the country with at least six fatal stabbings in recent days.

On Monday Theresa May, the Prime Minister, will host a major knife crime summit at Downing Street as the police desperately try to get a grip on the rising tide of violence.