French police have identified the suspect in a truck attack in Nice, that left at least 84 people dead and more than 100 injured, by his fingerprints.

According to France's "BFM TV", police managed to verify the identity of the suspect who drove a truck into a crowd watching the Bastille Day fireworks display late Thursday.

Investigators are comparing the fingerprints with an identity document found in the truck that belonged to a 31-year-old French-Tunisian resident of Nice with a criminal record, though with no links to terrorism, the French television channel reported.

A police operation was ongoing this morning in Nice, "France Info" reported.

The suspect was believed to have been in possession of a caliber 7.65 handgun, using it before being killed by police.

Larger guns and a hand grenade were also found in the truck, with unconfirmed reports claiming some of these weapons were fake.

The truck was rented in the region of Nice some days before the attack, and a credit card and mobile phone were also found, "BFM TV" said.