Spain said on Thursday it will send 313 police officers to Paris to bolster security for this summer's Olympic Games as France remains on high alert following attack threats.

The officers, including bomb deactivation experts and sniffer dog teams, will be deployed in response to a request from France for foreign assistance with Games security, the Spanish interior ministry said in a statement.

France, which will host the games from July 26 to August 11, has raised its security alert to the highest level after the deadly attack at a Moscow concert hall in March. The Islamic State group claimed responsibility for the massacre.

The Spanish police will stay in Paris for the Paralympics which will be held from August 28 to September 8, the statement added.

The French capital has been repeatedly hit by deadly attacks by Islamic extremists and security concerns are notably high for the opening ceremony of the Games, which will involve boats along the Seine River and huge crowds watching from the embankments.

Nearly 45,000 police officers and gendarmes will be mobilised in the Paris region for the event. During the games themselves, 18,000 French military troops will be deployed, including 3,000 responsible for aerial surveillance – in addition to about 35,000 police and gendarmes. (AFP)