PARIS • French police shot and injured a man who struck an officer with a hammer outside Notre-Dame cathedral in Paris yesterday and claimed "this was for Syria".

The attack comes after a weekend rampage in London, where extremists used a van and knives to crush to death and kill seven people, one of them French.

Hundreds of people were kept inside the famous cathedral, one of France's biggest tourist attractions, after the attack and Paris police said they would be progressively let out after routine checks.

French Interior Minister Gerard Collomb said the assailant shouted "this was for Syria" and seemed to have acted alone.

French TV reported scenes of panic during the latest incident, with tourists scrambling for cover.

France is under a state of emergency and on its highest possible level of alert following a string of terror attacks that began in 2015, which have killed over 230 people.

In the last fatal attack, a policeman was shot and killed on the Champs-Elysees avenue in Paris on April 20.

Last July, a radicalised Tunisian man drove a lorry at high speed through a Bastille Day fireworks display on the Nice waterfront, massacring 86 people.

There have been various smaller attacks since, often targeting security forces.

AGENCE FRANCE-PRESSE, REUTERS