A French teenager who tried to attack soldiers at the Eiffel Tower is undergoing a psychiatric examination to help determine whether he is fit for prosecution on terrorism charges.

Authorities say the 19-year-old man had been discharged from a psychiatric hospital soon before the tower incident Saturday, in which he brandished a knife at security forces and shouted "Allahu akbar," the Arabic phrase for "God is great." It was the latest of several attempted attacks on security forces guarding prominent French sites over the past year.

Authorities initially classified the case as a minor crime by someone with a history of psychiatric problems. They later upgraded it to a counterterrorism probe after the suspect told police he had been in contact with an Islamic State group militant and wanted to attack a soldier, according to an official close to the investigation.

The suspect, who turned 19 Monday, was born in Mauritania but has French citizenship, the judicial official said.

Read more: AP