A stabbing incident at a Tube station in east London is being deemed as a "terrorist incident", the Met Police said on Sunday.
Police were called to investigate reports of people being attacked at Leytonstone Tube station on Saturday evening. The attacker reportedly shouted "this is for Syria", BBC reported.
One man suffered serious knife injuries while two others received minor injuries.
Metropolitan Police have arrested one person and counter-terrorism detectives were investigating the case.
The Met said the suspect was reportedly threatening other people with a knife.
Fellow passengers reportedly shouted at the man to drop his weapon and one person shouted "You ain't no Muslim", a sentiment which has been picked up on social media by people trying to disown and sideline the attacker.
Another witness said he saw a man, who is believed to be aged 29, holding a knife, standing over another man who was lying on the ground, and people running out of the Central Line station.