LONDON (Reuters, AFP) - A suspect charged with attempting to kill a man at a London Underground train station had images associated with Islamic State in Iraq and Syria (ISIS) on his mobile phone, a court heard on Monday (Dec 7).

Muhaydin Mire, 29, appeared at Westminster Magistrates Court in London charged with the attempted murder of a 56-year-old man at Leytonstone station in east London on Saturday.

Prosecutors allege that the attack was an act of terrorism and images and flags associated with ISIS were allegedly found on his phone.

Wearing a grey t-shirt and grey track suit bottoms, Mire, of east London, spoke only to confirm his name, age and address at Westminster Magistrates' Court.

The 56-year-old unnamed man suffered serious but not life-threatening injuries in the attack at Leytonstone underground station, about 10 km east of central London, while a second person suffered minor injuries.

Prosecutor David Cawthorne said the attack occurred at 1900 GMT on Saturday (3am Sunday Singapore 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 suffered a 12-cm wound to his neck and was in surgery for five hours, he said.

Mire was remanded in custody to appear at London's central criminal court, the Old Bailey, on Friday.

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 in Iraq and Syria (ISIS) militants.

The authorities say British security forces have thwarted seven terrorism plots in the past year.

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

After the attacks claimed by ISIS in Paris on Nov 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.