Armed police deployed to rail and tube stations across London

A shopkeeper who witnessed the knife attack at Leytonstone tube station has described seeing a victim begging for help on the floor as he was punched, kicked and stabbed.

Salim Patel, 59, who runs the station shop and saw the attack unfold, said: "I was just at the shop when the train arrived and people came off.

A 56-year-old man suffered "serious" knife wounds, Scotland Yard said, but his injuries are not believed to be life-threatening.

He was taken by the London Ambulance Service to an east London hospital where he remains in a stable condition.

A second man sustained a minor injury during the incident but did not require medical assistance, while a woman was threatened but not injured.

A 29-year-old man was subdued by Taser and arrested at the scene.

Detectives investigating a violent knife attack at a London Underground station in Leytonstone are searching a residence in east London.

Amateur video obtained by ITV News shows people trying to get away from Leytonstone station as police confront the alleged attacker. Police say a taser was discharged during the arrest.

Witnesses say that after his arrest, he shouted: "This is for Syria."

ITV News correspondent Duncan Golestani reports:

An eyewitness of the stabbing attack in east London has told ITV News that he shouted "this is for Syria" after the attack.

The incident just after 7pm on Saturday is being treated as a terrorist incident by police.

One man was seriously injured and two sustained minor injuries, police said.

Labour leader Jeremy Corbyn has described the Leytonstone stabbing, that is being investigated by Counter Terrorism Command, as "absolutely shocking".

Police have confirmed they are treating multiple stabbings at Leytonstone station as a terror attack.

Police were called at 7:06pm to reports of a number of people stabbed at the station.

The man was reportedly threatening other people with a knife.

One man has sustained serious knife injuries - these are not believed at this stage to be life-threatening. Two other people have sustained minor injuries.

A man has been arrested after reports of a stabbing at Leytonstone station.

A Met Police spokesman said they were called just after 7pm to reports of a stabbing and people being threatened by a man with a knife outside the station.

The police are looking into whether there was more than one injury and how severe the injuries are.

The man was tasered and arrested.

British Transport Police have confirmed that a man has been taken to hospital and is currently receiving treatment after a reported stabbing at Leytonstone tube station earlier this evening.

A BTP spokesman said: