French prosecutors launched a terrorism investigation after a man wielding a knife and shouting "Allahu Akbar" tried to force his way in to the Eiffel Tower in Paris on Saturday night, a judicial source said.
The incident at the world-famous tourist landmark was designated a terrorism case because of the suspect's statements to police, in which he said he wanted to attack a soldier, and his apparent radicalisation, the source said.
No one was injured in the incident that occurred around 11.30 p.m. on Saturday shortly before closing time, Eiffel Tower operator SETE said in a statement on Sunday.
The man, brandishing a knife, tried to force his way through a security check before being stopped, it said. Police evacuated the tower to carry out a check of the entire site.
A source close to the investigation said the suspect, a French national born in Mauritania in 1998, had been in a psychiatric hospital for several months and was granted permission to leave care from August 4 to 6.
During police questioning, the man said he had wanted to carry out an attack against a soldier and had been in contact with a member of Islamic State who had encouraged him to act, the source said.
The suspect was convicted last December for defending acts of terrorism and for making death threats, the source said. He was given a four-month suspended sentence.
France has been under state of emergency legislation since November 2015 Islamist attacks in which 130 people were killed in and around Paris. Its interior minister said in a newspaper interview published on Sunday that the threat of militant attacks was "very high".
After pushing his way past a security guard at the entrance to the Eiffel Tower, the man approached soldiers patrolling at the site and, holding a blade, shouted 'Allahu Akbar', the source said.
But he complied when the soldiers told him to put down his weapon and offered no resistance when arrested, the source added.
Security forces have been targeted in several incidents this year, including two on the Champs-Elysees avenue and one outside Notre Dame Cathedral, also renowned tourist sites.
Militant attacks in France led to a drop in visitor numbers last year but activity has recovered in 2017.
The Eiffel Tower had been lit up on Saturday evening in the colours of soccer club Paris St Germain as part of festivities put on by PSG to welcome its world-record signing Neymar.