London, Dec 7 (IANS): Britain's counter-terror police searched a residential address in east London following a violent knife attack at a subway station.

Detectives from police service's counter terrorism command were investigating the attack that left a man severely injured on Saturday, Xinhua quoted the police as saying on Sunday.

A 29-year-old man wielded a knife and reportedly shouted "this is for Syria" before attacking commuters at Leytonstone Underground Station in east London.

The attack was being treated as a "terrorist incident", according to the police.

Police were called on Saturday to reports of a number of people stabbed at the station. The suspect also threatened other people with a knife.

The attacker, arrested for attempted murder, remains in custody at a police station in London.

"As a result of information received from people who were at the scene and subsequent investigations carried out by the Counter Terrorism Command (SO15), I am treating this as a terrorist incident," said police Commander Richard Walton.

"I would continue to urge the public to remain calm, but alert and vigilant. The threat from terrorism remains at severe, which means that a terrorist attack is highly likely," he added.

Police also urged witnesses to come forward and share with investigators the video footage they possess.