Trial in France for four involved in foiled 2015 Paris train attack

Four extremists have to go on trial today in France over a 2015 plot to attack Americans on a high speed train between Belgium and France. The extremists were tackled by four passengers including two off-duty American servicemen. On trial is Ayoub El-Khazzani, accused of opening fire on board the train. Three others on trial are suspected of helping El-Khazzani plan the attack.