A gunman reportedly linked to a militant group has driven a truck into a crowd in Nice, France, killing nearly 84 people and injuring more than 50.

The ‘terror attack’ occurred during the Bastille Day fireworks at the Promenade des Anglais on Thursday.

The driver was shot dead by the police and the truck he was driving contained weapons and grenades, according to media sources.

"He was known to the police for violence, and using weapons, but had no direct links with terrorism."

An investigation is underway to find out whether the driver alone was involved in the attack.

An investigating source was quoted by The Telegraph as saying: "He was known to the police for violence, and using weapons, but had no direct links with terrorism.

"His identity car was found in the lorry. He had French and Tunisian nationality."

French President François Hollande will extend the state of emergency in the country, originally due to end on July 26, for another three months.

The country had been on high alert since November 2015 after more than 130 people were killed and hundreds were wounded in series of terrorist attacks in Paris.

The BBC quoted Hollande as saying that operational reserves will support the army and security forces across the country in tackling the situation, with focus on the borders.

No terror groups have so far have claimed responsibility for the attack.