"We are still exposed," Hollande said on Tuesday in an address to diplomats in Paris. "The aggression that took place on Friday…which could have degenerated into monstrous carnage…is fresh proof that we must prepare for other attacks and therefore protect ourselves."

Last week, several passengers, including three US and one British citizen overpowered a gunman aboard a high-speed train from Amsterdam to Paris, preventing a potential massacre. Over 550 people were traveling on the train.

The attacker, a 25-year-old Moroccan, was carrying a Kalashnikov and several other smaller weapons, including a Luger automatic pistol, ammunition and a box cutter.

Under French law, officials can question the accused, for four days, after which they must either charge or release him. French authorities were in the last phase of interrogating the attacker, who was under the scanner of Spanish counter-terrorism authorities for making speeches defending jihad, AFP news agency quoted an unnamed Spanish source as saying.

According to his father, the Morrocan left for a work contract with phone operator Lycamobile. He came to the attention of French intelligence after German officials alerted them of the man's travel to Syria via Turkey in May.

'Difficult to believe'

The 25-year-old has denied any terror links, saying he was "dumbfounded" after he was suspected of being an Islamist. He said he came across the stash of weapons in a park in Belgium and was actually only looking to rob passengers because he was hungry, his lawyer at the time, Sophie David, told reporters.

The Moroccan's plans were foiled after three US citizens, including two off-duty soldiers and a university student, a British citizen, a Frenchman and another US national living in France, overpowered him. US Air Force Serviceman Spencer Stone, National Guardsman Alek Skarlatos and California resident Anthony Sadler, all in their early twenties, received the Legion of Honor in Paris on Monday.

Stone, who sustained a lacerated thumb and an eye injury while tackling the gunman, has also been nominated for the US Air Force's highest medal for non-combat bravery. He and his friend, Skarlatos, are now in Germany for health checks.

Chris Norman, the British citizen who helped overpower the assailant, said "it was a little bit difficult to believe that it's actually happened."

Meanwhile, another US citizen, Mark Moogalian, who helped subdue the attacker was being treated in a hospital in Lille after being shot in the neck. In an interview with broadcaster Europe 1, his wife said her husband had noticed a passenger with a suitcase spending a long time in the bathroom. Moogalian, who has been living in France for over two decades, received a bullet as he went forward to take the rifle away from the gunman, who was being held by another traveler from behind.

The other passenger, believed to be French, has requested to remain anonymous. He and Moogalian are also to receive the Legion of Honor shortly.

mg/kms (AFP, AP)