A man who appeared in court charged with attempted murder after a stabbing at London Underground train station was allegedly found with pictures associated with the Islamic State (IS) militant group on his phone.

Muhaydin Mire, 29, from east London, is accused of attempting to murder a 56-year-old man at Leytonstone station, about 10 kilometres east of England’s capital.

Eyewitnesses said the suspect shouted out “this is for Syria” during the attack, which police have described as a terrorist incident.

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Mire was driven to court in a police van escorted by other vehicles which went into the court building through a back entrance and appeared at the Old Bailey wearing a light grey T-shirt and tracksuit trousers.

During a brief hearing, he spoke only to confirm his name, date of birth and address.

Prosecutor David Cawthorne said the attack occurred on Saturday evening (local time) as the victim walked through the station.

“It was a violent, sustained and unprovoked attack during which the victim was punched, knocked to the ground and repeatedly kicked on the ground,” he said.

The victim, referred to in court as Male A, was in surgery for five hours after the attack, the prosecution said.

Prosecutors also allege that images and flags associated with IS jihadists were subsequently found on Mire’s mobile phone.

Mire was remanded in custody until Friday (local time) when he will again appear at the Old Bailey in London, the Central Criminal Court of England and Wales.

British prime minister David Cameron described the attack as hideous.

“First of all, full credit to the person and people who took on this attacker, and full credit to the very brave police officers who managed to subdue him,” he told reporters.

He also paid tribute to an eyewitness who can be seen in a video of the incident shouting to the attacker: “You ain’t no Muslim bruv! You’re no Muslim bruv! You ain’t no Muslim!”

“Let me also pay credit to the person … who made that brilliant statement about ‘You ain’t no Muslim’,” Mr Cameron said.

Britain is on its second-highest security alert level of “severe”, meaning a militant attack is considered highly likely, though not imminent, mainly because of the threat posed by Islamic State militants in Syria and Iraq.

British security forces have thwarted seven terrorism plots in the past year, authorities said.

Last week, British war planes joined air strikes for the first time against IS fighters in Syria.

After the attacks claimed by Islamic State militants in Paris on November 13, which killed 130 people, police in London said they had boosted the number of armed officers able to respond to any incidents.

Deputy Chief Constable Adrian Hanstock from the British Transport Police said the number of firearms teams had doubled in the last year and they had boosted the number of officers and patrols across the London underground network in response to Saturday’s stabbing.

“We work very closely with all our intelligence partners and if we do have any indication there is likely to be something significant we intervene,” he told BBC radio.