According to Reuters, a knife attacker slashed a man at an east London metro station, reportedly screaming “This is for Syria!”, in what police described as a terrorist incident, prompting a senior minister to urge Britons on Sunday not to be intimidated.

A pool of blood near the ticket barriers at the Leytonstone Underground station, about 10 km east of central London, could be seen in footage posted on Twitter that also showed the suspect confronting police on Saturday evening. Police said the man, believed to be around 29 years old, had also threatened other bystanders. One man, thought to be 56 years old, suffered serious but not life-threatening injuries and was in a stable condition at a London hospital. A second victim suffered minor injuries.  

“I am treating this as a terrorist incident,” Richard Walton, who leads the Counter Terrorism Command at London’s Metropolitan Police, said in a statement. The man was arrested after police used a Taser to subdue him.

Detectives were searching a residential address in east London and additional officers were being deployed to the rail transport network, police said.

An eyewitness quoted by the Guardian said the attacker appeared to claim that he was retaliating for Western air strikes on Islamist militants in Syria, shouting: “This is what happens when you f*** with mother Syria, all of your blood will be spilled!” In an interview with the Sunday Times, Syrian President Bashar al-Assad mocked Cameron’s strategy, saying it would make the situation worse, not better.

As police rushed to arrest the man, one witness can be heard shouting ‘You ain’t no Muslim bruv’ before the attacker is tasered and pinned to the ground. It is understood the attacker is “Somalian or Sudanese” and spoke in “an Arabian accent”.

However, it was the onlooker’s comments which went viral with the #YouAintNoMuslimBruv trending on Twitter.

Writer Tony Parsons tweeted: “Proud of my city today. #YouAintNoMuslimBruv.”

Bonnie Greer’s tweet read tweeted: “Reports that someone yelled at perp: #YouAintNoMuslimBruv ! Yes..that sounds like a Londoner to me.”

Muthla wrote: “Best trend I’ve seen – YouAintNoMuslimBruv regarding horrific attack in Leytonstone. Gotta love London for the trend!”

Another called Jackie Nn wrote: “youaintnomuslimbruv- soo proud to be a Londoner. True Muslims don’t try and kill innocent bystanders. Peace to true Muslims.”

Chris Lowndes wrote: “YouAintNoMuslimBruv is just perfect – real, inclusive, undermines terrorist cause.”