Truck attack in Nice: what we know so far

At least 84 people have been killed after a truck slammed into a crowd of people celebrating Bastille Day in the southern French city of Nice.

Here is what we know about what French President François Hollande has declared an "undeniable" terrorist attack.

How the attack unfolded 

The large white truck plunged into the crowd at around 11:00pm (2100 GMT) Thursday night as hundreds of people were on Nice's beachfront Promenade des Anglais to watch the fireworks for France's national day.

A spokesperson for the Interior Ministry confirmed that at least 84 people had been killed after the truck ploughed two kilometres (1.3 miles) through the crowd, who had just finished watching the firework show.

As rumours swirled online, the Ministry dismissed reports that people had been taken hostage.

According to witness testimonies confirmed by a police source, the driver pulled out a gun and fired at the crowd before being shot dead.

Multiple bullet holes were visible in the truck's windscreen as police moved in after the carnage.

"Probably the most realistic type of attack because it's not obvious"

What we know about the attacker

FRANCE 24 is not releasing the name of the attacker, but identity papers of a 31-year-old Tunisian were found in the truck that matched the dead attacker, officials said. The papers indicate the man is a Nice resident who was known to police for common law crimes, but not to intelligence services. He had been living legally in France, the officials said.

The alleged attacker had previous misdemeanor convictions but no links to extremist groups.

Was this a jihadist attack?

The attack has not been claimed by any group, but Hollande said in an address to the nation early Friday that the attack was of an "undeniable terrorist nature".

Prosecutors say the probe will be handled by anti-terrorism investigators. Interpol said it has deployed an incident response team to Nice. The team includes terrorism and information specialists who will carry out real-time checks against global databases, the France-based international police organization said.

"Investigations are currently underway to establish if the individual acted alone or if he had accomplices who might have fled," interior ministry spokesman Brandet said.

The attack comes with France under a state of emergency following the Islamic State group attacks in Paris in November that left 130 people dead.

How has the government reacted?

Hollande announced that the state of emergency would be extended by three months and army reservists called up to boost security.

He also said France would strengthen its role in Iraq and Syria, where it is part of the international coalition fighting IS group jihadists.

He will chair a meeting of top military and security officials later Friday to decide on possible further steps.

Has anything like this happened in France before?

In December 2014, two men ploughed their vehicles into pedestrians in two days -- separate incidents that left France reeling.

The first driver shouted "Allahu Akbar" (God is greatest) as he drove into people in the eastern city of Dijon, injuring 13.

The 40-year-old had a long history of mental illness, and no ties to jihadist groups, the government said.

A day later, a man rammed a white van into a Christmas market in the western city of Nantes, killing one person and injuring nine others. He then stabbed himself several times.

Prosecutors said a notebook was found in his vehicle in which he spoke of his "hatred for society" and said he feared "being killed by secret agents".

The man committed suicide in his prison cell in 2016 while awaiting trial.