LONDON (Reuters) - A man who stabbed a passenger at a London underground train station in December while shouting that he was acting for Syria was jailed for life at a London court on Monday.

Muhaydin Mire, 30, of east London, beat his victim, forced him to the ground and kicked his head before attempting to cut his neck, leaving the man with a 12-cm (5-inch) gash that required five hours of surgery.

He will serve a minimum of 8-1/2 years in prison after being convicted of attempted murder at London's Old Bailey criminal court on June 8.

Initially described by police as a "terrorist incident", the attack at Leytonstone station in east London was investigated by the Metropolitan Police's Counter Terrorism Command.

"Whilst Mire was not accused of terrorist offences, it would appear from comments he made at the time of the attack and the content he had downloaded on his phone that he may have been inspired by terrorist propaganda," said Commander Dean Haydon in a statement.

Mire, who tried to attack several other people during the incident, had pleaded guilty to four counts of attempted wounding but denied trying to kill his victim.

Several people filmed the incident on their phones. Some of the videos were posted on the Internet shortly after the attack, including footage of a bystander shouting "You ain't no Muslim, bruv (brother)," a phrase which circulated widely and was praised by then Prime Minister David Cameron.

The Leytonstone incident took place on Dec. 5, a time of heightened tension over Islamist militancy in Europe following the Nov. 13 attacks that killed 130 people in Paris.

(Reporting by Estelle Shirbon; editing by Stephen Addison)