An attacker at Paris Notre Dame cathedral carrying an Algerian student card allegedly shouted "this is for Syria" as he attacked one of three police officers with a hammer, French interior minister Gerard Collomb says.
"A man came behind these police officers and, armed with a hammer, started hitting one of them. His colleagues reacted with composure...and fired," Collomb told reporters near the cathedral in central Paris, following the incident on Tuesday.
Collomb added that the injured attacked was being treated in hospital and seemed to have acted alone.
Following the incident the Paris prosecutor's office swiftly launched a counter- terrorism investigation.
Armed police cordoned off the site and the cathedral in central Paris that is visited by millions of tourists every year was locked down during the incident.
It comes just three days after Islamist militants killed seven people in London in a knife and van attack.
"Situation under control, one policeman injured, the assailant was neutralised and taken to hospital," Paris police said on Twitter.
Two police sources said the officers shot the assailant in the thorax after he had threatened them with a hammer and refused to stop. One policeman was hurt, according to one source.
Karine Dalle, a spokeswoman for the Paris diocese, told BFM TV 900 people were inside the cathedral as police secured the area.
One holidaymaker inside Notre Dame wrote on Twitter: "Not the holiday experience wanted. Trapped in Notre Dame Cathedral after police shoot a man. We are with our 2 terrified children."
France is under a state of emergency after a wave of militant attacks since early 2015 that have killed more than 230 people across the country.
Three women were arrested in September after police found a car laden with gas cylinders abandoned near Notre Dame cathedral in what the interior ministry at the time said was a likely planned imminent attack.