Man stabs 3 people in London tube, detained by police

A man stabbed three people in the London Underground on Saturday night, seriously injuring one man and wounding two other people.

According to the UK's The Telegraph newspaper, people witnessed him yell: "This is for Syria."

Scotland Yard has decided to treat the attack as a "terrorist incident".

"We are treating this as a terrorist incident," counter-terrorism leader Commander Richard Walton said in a police statement.

Amateur video footage circulating on the Internet showed a pool of blood and bloody footprints at the Tube station ticket gates at Leytonstone, east London.

Some commuters continued on their journey while others briskly moved away from the scene.

Footage shows an officer shouting "Drop the knife!" and firing a Taser electric stun-gun.

A later clip shows the man being pinned to the ground by police as passers-by are told to get back.

One man at the scene shouted: "You ain't no Muslim, bruv."

A spokeswoman from London's Ambulance Service said emergency services "were called at 7:09pm to reports of an assault at Leytonstone underground station".

"We sent a number of resources to the including our joint response unit, an incident response officer, an ambulance crew and London's Air Ambulance to the scene," said the spokesperson.