French authorities have formally opened a terrorism investigation fter a thwarted attack on a high-speed train last week, saying the suspected attacker had watched a radical video onboard minutes before the violence.

Prosecutor François Molins said on Tuesday the decision to open an investigation was based on the actions of 26-year-old Moroccan suspect Ayoub el-Khazzani on the train on Friday night and information from other European authorities about his travels and apparent links to radical Islam.

Molins said Khazzani watched the online video on his phone minutes before he walked through the Amsterdam-to-Paris train carrying an assault rifle and other weapons.

Authorities said they found the suspect’s phone in a bag left in the train, which Khazzani boarded on Friday at a Brussels station.

The gunman was tackled and tied up by a group of three American friends and a British businessman. Another man who tried to stop him – a French American named Mark Moogalian — remains in hospital with a gunshot wound.

Magistrates are expected to file several charges against Khazzani, including attempting a terrorism-related attack.

Khazzani was found to have an AKM assault rifle with 270 rounds of ammunition, a 9mm handgun, a box-cutter and a bottle of petrol, the prosecutor said.

Khazzani had travelled through several European countries and had been repeatedly detained in Spain, Molins said. He may also have tried to travel to Syria.

In questioning, Khazzani initially said he had found a bag of weapons the night before in a Brussels park and planned to use them to rob passengers, according to Molins. But his explanation grew less and less lucid, the prosecutor said, and the suspect eventually stopped speaking to investigators at all. The Guardian