THREE people were wounded when a gunman opened fire on a high- speed train last night.
The suspect was grabbed by two unarmed US Marines as he came out of a toilet brandishing a Kalashnikov.
They had been standing nearby and heard him cocking the gun.
Two victims, including one of the marines, were believed to be critically ill after the incident on the Paris-Amsterdam service.
The suspect, a 26-year-old Moroccan, was also carrying nine full magazines of ammunition, a handgun and a knife.
He was arrested after the train stopped in Arras, northern France.
Later dramatic photos emerged of him being pinned to the floor of the carriage and then being held down by armed police.
A man with a bandaged head was taken away in a wheelchair.
Initial reports said a Brit was among the wounded, but the Foreign Office denied this.
The attack reportedly happened as the train passed through Belgium. Some passengers even jumped off of their carriages in the town of Henin-Beaumont.
Witness Patrick Arres, 51, said: “The train stopped in open country before Arras. I saw four to five people from the train, behind the embankment crying.”
It is understood the suspect was known to security services.
France has been on high alert since Islamist militants killed 17 in and around Paris in January.