PARIS (AFP) -- The suspect in the attack on a high-speed train in France looked at an online video of jihadist songs on his mobile phone shortly before boarding, a source in the investigation said on Tuesday.

Ayoub El Khazzani "looked at this video between the time that he bought his ticket and the time he boarded the train" a few hours later, the source said.

He was initially thought to be carrying two phones, but the source said he was actually only in possession of one mobile phone, which had been activated on the morning of the attack.

Khazzani, 25, boarded the high-speed train in Brussels on Friday armed with a Kalashnikov assault rifle, a Luger automatic pistol, ammunition and a box-cutter.

He is being questioned by anti-terror investigators, who have until Tuesday evening to charge or release him, though he insists he had only been seeking to rob passengers.