A man who allegedly screamed "this is for Syria" as he slashed a passenger's neck in a London subway station had images associated with the Islamic State group on his mobile phone, prosecutors said Monday.

Muhaydin Mire, who has been charged with attempted murder, also allegedly had images relating to the Nov. 13 gun and bomb rampage in Paris and a recent British police anti-terrorism training exercise.

Prosecution lawyer David Cawthorne told a court hearing Monday that prosecutors allege Saturday's knife attack at Leytonstone Underground station was an act of terrorism.

Passers-by recorded the aftermath of the incident on their phones. In one clip, as police officers wrestled the suspect to the floor, a bystander yelled: "You ain't no Muslim, bruv."

The terse dismissal, spoken in a distinct London accent - complete with the slang term bruv, for brother - raced round social media, with the hashtag YouAintNoMuslimBruv becoming a top trending topic on Twitter.

Mire, who is 29 and lives a few blocks from the east London subway station, appeared Monday at Westminster Magistrates' Court.

Cawthorne, the prosecutor, said Mire launched a "violent, sustained and unprovoked" attack on a 56-year-old man, who was punched and kicked to the ground before being slashed in the neck during the attack. He required five hours of surgery on a 12-centimeter (5-inch) wound and is in stable condition in a hospital.

A written summary of the prosecution case disclosed in court included details of the IS-related material found on the suspect's phone.

Mire - who was arrested after police officers used a stun gun to subdue him - spoke only to confirm his name, age and address. He was ordered detained until a court appearance on Friday.