The assailant who stabbed a man in London’s Leytonstone tube station today shouted “This is for Syria” before attacking him, according to witnesses. Two others were slightly wounded in the incident. Unlike the mass shooting in San Bernardino, authorities aren’t wasting any time treating the attack as a terrorist incident.

BBC News reports that one man suffered serious knife injuries before the attacker was Tasered by police and arrested.

The Metropolitan Police’s Counter-Terrorism Command is investigating.

Editor’s note: The following video includes a brief but graphic shot of a pool of the victim’s blood that some readers might find disturbing.