Authorities responded to an incident near Notre Dame Cathedral in Paris after a man attacked an officer, police confirmed to multiple media outlets.

Cedric Michel, a police union official, told the Associated Press that the suspect was armed with a hammer. The Paris police department tweeted that one officer was wounded. The police shot the suspect, who was hospitalized.

The cathedral was put on lock down. One person inside the cathedral tweeted that everyone there was safe and shared a photo.

Those inside the cathedral were cleared out after a security check on the area.

French Interior Minister Gerard Collomb spoke after the attack. He said that the attacker cried "it's for Syria" when he went after the officers.

Collomb said that police found kitchen knives and a hammer on the suspect. Paris prosecutors have opened a counterterrorism investigation.

Collomb also said French President Emannuel Macron will deliver a statement on Wednesday on how to combat terrorism.

France remains under high alert following a string of attacks in recent years.

In January 2015, two Islamist gunmen killed 17 people at the Paris office of satirical magazine Charlie Hebdo. A series of terrorist attacks killed 130 in November 2015. In April, an officer was killed after an attacker open fired on a police van at Champs Elysees.

This story is developing and will continue to be updated.