Updated 19:00
A man armed with a hammer and kitchen knives has attacked police officers outside Notre Dame cathedral in Paris.
Police says a perpetrator has been 'neutralised', and the situation is now under control.
One officer suffered minor neck injuries during the assault in the cathedral's courtyard before the lone attacker was shot and wounded.
French interior minister Gerard Collomb said the attacker was carrying the ID card of an Algerian student, and had cried: "This is for Syria."
The world-famous landmark, which is visited by millions of people a year, was locked down during the incident - with French TV reporting that tourists were fleeing the scene.
Hundreds of tourists were kept inside the cathedral as armed police responded - and one picture showed visitors with their hands in the air.
Police in the French capital warned people to stay away from the site, on the Ile de Cite island on the River Seine.
🔴Parvis de #NotreDame Intervention en cours des effectifs de police, évitez le secteur
— Préfecture de police (@prefpolice) June 6, 2017
Reuters reports that the attacker was shot in the chest and has now been taken to hospital - but his motive remains unclear.
"There was a crowd surge and people panicked. I heard two shots and saw a man lying on the ground in a pool of blood," one witness said.
Although the hour-long operation at Notre Dame has ended, France's counter-terrorism office has opened an investigation.
A source close to the investigation told the AFP news agency that the suspect has claimed to be a "soldier" of Islamic State.
Counter-terrorism
At a news conference, Mr Collomb stressed that the fight against terrorism is President Emmanuel Macron's number one priority.
Robbie Thomas, who was visiting Notre Dame at the time, told Sky News that "probably a couple of thousand" people were inside the cathedral when the attack began.
He said everyone had remained calm and were "trying not to panic" as they awaited announcements from police.
"A man I spoke to ran in from outside because he heard gunshots," Mr Thomas added.
Those who were trapped inside were gradually being allowed to leave once "usual" security checks had taken place:
🔴 Parvis de #NotreDame Le public confiné lors de l'intervention va être progressivement autorisé à sortir après les vérifications d'usage
— Préfecture de police (@prefpolice) June 6, 2017
Paris is on high alert following a series of Islamic extremist attacks in recent years - with soldiers patrolling the city's streets along with police to protect tourist sites, government buildings and events.
In September, three women were arrested after police found a car loaded with gas cylinders abandoned near Notre Dame - with France's interior ministry saying it was likely to have been an imminent attack.
