French police say they have shot a man outside the cathedral of Notre-Dame in Paris, after he tried to attack an officer using a hammer, the BBC reports.
Police have closed the area and are asking people to stay away. Reports say the attacker has been injured and his condition is not clear.
Eyewitnesses reported tourists fleeing for cover.
France is in a state of emergency since attacks by jihadists in Paris left 130 people dead in 2015.