Nice attack: What we know and don't know
At least 80 people have been killed after a truck slammed into a crowd of people celebrating Bastille Day in the southern French city of Nice.
French President Francois Hollande has declared it an "undeniable" terrorist attack.
Here is what we know about the attack so far:
1. 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.
2. Christian Estrosi, head of the local region, said guns and "larger weapons" were found in the truck.
3. Hollande said at least 77 people including children were killed after the truck ploughed two kilometres (1.3 miles) through the crowd, who had just finished watching the firework show.
4. As rumours swirled online, interior ministry spokesman Pierre-Henry Brandet dismissed reports that people had been taken hostage.
5. The attacker has been shot dead, Hollande said.
6. He is yet to be named, but the identity papers of a 31-year-old French-Tunisian were found in the truck, according to a police source. The papers indicate the man is a Nice resident.
7. Prosecutors say the probe will be handled by anti-terrorism investigators. "Investigations are currently underway to establish if the individual acted alone or if he had accomplices who might have fled," Brandet said.
8. Hollande announced that the state of emergency would be extended by three months and army reservists called up to boost security. The attack comes with France under a state of emergency following the Islamic State attacks in Paris in November that left 130 people dead.
9. He also said France would strengthen its role in Iraq and Syria, where it is part of the international coalition fighting IS jihadists. He will chair a meeting of top military and security officials later Friday to decide on possible further steps.
What we don't know
1 . Who committed the attacks, and why.
2 .The attack has not been claimed by any group.