British police have described a stabbing at a London subway station as a �terrorist incident� which left at least three people injured, one seriously, with the suspect reportedly under arrest.

According to Met police, the Saturday incident occurred at the Leytonstone station in east London just past 19:00 GMT leading to the arrest of the knife-wielding suspect.

Authorities further added that injuries of the most seriously wounded victim �were not believed to be life-threatening, noting that the assailant was threatening other people in the subway station with the knife.

"We are treating this as a terrorist incident. I would urge the public to remain calm, but alert and vigilant,� said Commander Richard Walton, who leads the police counter-terrorism unit.�"The threat from terrorism remains at severe, which means that a terrorist attack is highly likely.�

Meanwhile, video footages of the incident have been posted on the internet, purportedly showing the attacker in the station as well as attempts by police officers to taser him and take him into custody.

The video shows the suspect collapsing to the ground and dropping what appears to be a small knife.

By Press TV