Liberte Egalite Fraternite! SOLIDARITE with France! No terror will ever defeat democracy & liberty. #NiceAttack pic.twitter.com/TtYorTRYHp

— Peter Tatchell (@PeterTatchell) July 15, 2016

A truck mowed through a crowd on a seaside promenade during a Bastille Day celebration in the French city of Nice in what President Francois Hollande called an attack of “a terrorist nature.”

On Friday, Hollande extended a state of emergency for three months after the attack, which French officials said has killed at least 84 people, including children. About 50 people were wounded, 18 of them critically, officials said.

The attack took place during a fireworks display Thursday night marking France's most important annual holiday. Social media video showed people running through the streets in panic following the attack.

The truck drove about a mile on the promenade. In a Twitter message, Christian Estrosi, the mayor of Nice, said the truck was carrying arms and explosives when it struck the crowd at about 10:30 p.m. local time.

Authorities said the truck driver was shot dead. Police say ID found with the attacker was of a French petty criminal, 31, of Tunisian descent, the AP reported. There was no DNA confirmation.

Interior Ministry spokesman Pierre-Henry Brandet said officials were investigating whether the driver acted alone. Paris-based journalist Vivienne Walt said there were reports of a second person in the truck who fled.

There was no immediate claim of responsibility.

“Nobody seems to have much doubt or ambiguity as to what this incident was,” Walt told PRI's The World.

7. See other screengrabs below showing how this is playing on channels that espouse ISIS' ideology: pic.twitter.com/A61KYFnm9c

— Rukmini Callimachi (@rcallimachi) July 15, 2016

Rebecca Giraud described her restaurant as 20 meters from the attack. Before the attack, she said, “It was really a great night for us … We were full all night long.”

Then, she heard screams and “everybody was running into the restaurant. … We were so afraid.” She told The World that they hid the people upstairs and in the basement, not knowing who was behind the attack. They left the restaurant without cleaning up later, and it was going to be closed on Friday.

“We will try to sleep,” Giraud said shortly after 2 a.m., “but it won't be easy tonight.”

President Barack Obama, in a statement, condemned the attack and said the United States stood by France.