There was an exchange of gunfire in the aftermath of the incident before the driver was shot dead by police.

A second suspect is thought to have escaped and is on the run. ISIS (ISIL , IS , Islamic State , Daesh) has claimed responsibility for the attack, according to unconfirmed reports in the French media.

Guns and grenades were found inside the truck, which mounted the pavement at approximately 40mph and drove for a mile mowing down hundreds of people.

Bodies - including those of children - were left strewn across the ground as blood streamed through the streets, where just moments earlier families had excitedly huddled to watch a firework display celebrating the French public holiday.

Anti-terror police swooped in as the city was put on lockdown and residents were warned to stay indoors for their safety. Gunshots rang out in the streets, with gunmen targeting hotels and cafes in the port city in the south of France.

The Bastille Day truck attacker was a 31-year-old French-Tunisian, who was born in Tunisia, a police source has told Reuters.

They added the attacker was known to police for common law crimes, but was not known to intelligence agencies.

The driver reportedly emerged from the lorry shooting at people.

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