Three people have been hurt after a heavily armed man opened fire on a train in northern France, before being overpowered by two American passengers. The incident happened on the high-speed Thalys service near Arras, and the attacker was arrested at Arras station. The interior minister praised the Americans, one of whom was seriously injured, as was another passenger. The man arrested was a 26-year-old Moroccan. Anti-terrorist officers have taken over the case. The weapons were said to include a Kalashnikov, a knife, an automatic pistol and cartridges. As a gunman on an Amsterdam-to-Paris train was about to launch an attack by loading his Kalashnikov he was surprised by two U.S. Marines in civilian clothing, a senior European counterterrorism official told CNN. The gunman fired on them with a handgun, the official said. He wounded at least one of them, but was overpowered. The suspect had several weapons and lots of ammunition, the official said, saying the Marines prevented a massacre.