Greek-American Alek Skarlatos and another two US citizens who overpowered a gunman on a train between Amsterdam and Paris on Friday were invited to the Elysee Palace by French President Francois Hollande on Saturday and praised by President Barack Obama as heroes.

Skarlatos, a 22-year-old member of the Oregon National Guard who had recently returned from service in Afghanistan, said he and two friends, another army officer, Spencer Stone, and Anthony Sadler, a student, had been on the train when they saw a man enter holding a Kalashnikov.

Stone tackled the gunman but was cut with a knife.

The friends then disarmed the suspect, beat him until he was unconscious and bound him.