Three people have been wounded in a shooting on board a high speed train en route from Amsterdam to Paris.
One of those reportedly injured is American, another from Britain and the nationality of the third person is unknown.
The main suspect is believed to be in 20s and under police custody in the northern town of Arras.
The assailant was reportedly armed with both a Kalashnikov rifle and knives.
French anti-terrorist police are investigating the incident.