Police Quiz Gunman over French Train Attack

French investigators were on Saturday interrogating a man who was overpowered by two young American servicemen after he opened fire with a Kalashnikov on a train between Amsterdam and Paris.

The suspect is thought to be a 26-year-old of Moroccan origin who had lived in Spain, said French Interior Minister Bernard Cazeneuve.

He was "signaled by the Spanish authorities to French intelligence services due to his membership of the radical Islamist movement," Cazeneuve told reporters, saying he was living in Spain last year but had moved to Belgium in 2015.

Armed with a Kalashnikov assault rifle, an automatic pistol, nine cartridge clips and a box-cutter, the man opened fire on board the TGV train just after it crossed from Belgium into France on Friday evening.

But the attack was quickly stopped when two off-duty American soldiers and a friend charged the gunman and overpowered him.

"I looked back and saw a guy enter with a Kalashnikov. My friends and I got down and then I said 'Let's get him'," Alek Skarlatos, a 22-year-old member of the National Guard in Oregon, told France's BFMTV.

Spencer Stone, who is reportedly in the U.S. Air Force, was the first to reach the gunman who slashed him in the neck and hand with a box-cutter.

"At that point I showed up and grabbed the gun from him and basically started beating him in the head until he fell unconscious," said Skarlatos, who recently returned from service in Afghanistan.

Their friend, U.S. student Anthony Sadler, told French TV the attacker "didn't stand a chance."

"He didn't say anything. He was just telling us to give back his gun. 'Give me back my gun! Give me back my gun!' said Sadler.

A British man, Chris Norman, was also praised for helping the group, as was a Frenchman who had earlier tried to stop the gunman when he came across him in a toilet.

"The French passenger courageously tried to tackle him before the attacker fired several shots," said Cazeneuve.

The train heroes are due to be received by President Francois Hollande at the Elysee Palace "in the coming days", his office said in a statement.

Stone was taken to hospital along with another unnamed American passenger, who was hit in the shoulder with a bullet. Neither are in critical condition, Cazeneuve said.

Mobile phone footage from inside the train and played on several TV stations shows the suspect, a skinny man wearing white trousers and no shirt, flattened on the floor of the train with his hands and feet tied behind his back.

A Kalashnikov is seen leaning against a seat and blood is visible on a window.

"I'm just a college student," said Sadler. "I came to see my friends for my first trip to Europe and we stop a terrorist. It's kind of crazy."

President Barack Obama praised the passengers, saying "it is clear that their heroic actions may have prevented a far worse tragedy."

Analysts said it was not surprising someone could launch an attack even though he was on a watch-list.

"It's the perennial problem of how you prioritize between serious concerns," said Raffaello Pantucci, counter-terrorism expert at Royal United Services Institute in London.

"It's a very resource-intensive job to watch someone 24 hours a day. Intelligence agencies just aren't big enough to do that for everyone," he said.

France has been on high alert since Islamist gunmen went on the rampage in January, killing 17 people in Paris.

In June, a man beheaded his boss and tried to blow up a gas plant in southern France in what prosecutors say was an attack inspired by the Islamic State group.

The man, who began shooting at 5.50 pm (1550 GMT), was arrested 10 minutes later when the train with 554 passengers aboard stopped at Arras station in northern France, a railway spokesman said.

One of the passengers, who asked to be identified only as Damien, 35, said he had heard the gunman shooting but initially thought the sound came from a toy.

"The man stopped between two carriages, fired and it made a click-click-click sound, not at all like in the films," he said, still clearly shocked.

French actor Jean-Hugues Anglade, who appeared in the 1986 cult film "Betty Blue" staring Beatrice Dalle, suffered minor injuries as he tried to activate the train's alarm, a spokesman for SNCF said.