At least 80 people are dead after a man intentionally drove a truck into Bastille Day revellers in the resort city of Nice, and French President Francois Hollande says the victims include “many children.”

“This attack’s terrorist character cannot be denied,” he said in a speech delivered around 3:30 a.m. local time. “All of France is under threat from Islamic terrorism,” he added.

Hollande said the driver of the truck had been shot and killed, and authorities are working to identify him.

“France was hit on its national day, July 14, a symbol of freedom,” he added. “Because human rights are denied by fanatics, France is their target.”

Hollande said he had mobilized 10,000 military personnel and was calling up all those who had served in the army to help prevent terrorism and patrol the country’s borders.

“Nothing will break our will to fight against terrorism and we will once again strengthen our actions in Syria and Iraq and continue to strike those who are attacking us,” he said.

The president announced a three-month extension of the country’s state of emergency, which he had said – just hours earlier – would end on July 26.

The attack happened around 10:30 p.m., just as tourists and locals were gathered on the city’s famous Promenade des Anglais to watch fireworks over the Mediterranean Sea.

Christian Estrosi, a regional politician, told BFM the truck was loaded with “arms and grenades” and the “the driver fired on the crowd, according to the police who killed him.”

The Paris prosecutor's office said Thursday night that it had opened an investigation for "murder, attempted murder in an organized group linked to a terrorist enterprise."

U.S. President Barack Obama condemned the attack and praised the French for “extraordinary resilience and democratic values that have made France an inspiration to the entire world."

Eyewitness account

Eyewitness Lee Jewell told CTV News Channel she was watching the fireworks at a restaurant with her husband when she saw panicked people running past them.

Jewell said she then saw a white delivery-style truck rolling down the promenade, which had been closed to traffic.

Jewell said two people running alongside the truck appeared to be dressed in “military type clothing.” She found that “suspicious.”

When gunfire rang out, she and her husband hid behind a car.

Jewell said she did not see the truck plow into the pedestrians, but in their rush back to their hotel, they witnessed “no (fewer) than 30 dead bodies covered with sheets in the street.”

“There were people running up with blood streaming from their arms and knees from injuries,” she said. Police were administering first aid. She saw one “step aside to vomit.”

Jewell added that security had seemed extensive earlier in the evening. They saw one man stopped so that authorities could search his backpack.

Grace Ann Morrow was walking home from the fireworks when she started hearing screams and saw “hordes of people erupting from the street screaming bloody murder.”

“Hundreds of people were running, pushing, moms carrying their children, kids crying, people looking around, some people just standing there,” Morrow told CTV News Channel.

Morrow ran against the crowd. When she saw military personnel lining up, she realized she should “probably start running (the other way) because there’s something awful going on.”

Canadian travel warning

Prime Minister Justin Trudeau tweeted that Canadians are “shocked” by the attack, adding, “Our sympathy is with the victims, and our solidarity with the French people.”

Ottawa was working to confirm whether any Canadians were among the victims.

Foreign Affairs Canada updated its travel advisories late Thursday to say that although there is “no nationwide advisory in effect for France … Canadians should exercise a high degree of caution due to the current elevated threat of terrorism.”

France is “used to this”

Local newspaper reporter Oliver Gee told CTV News Channel that “it’s a real blow” to France, although the country is “getting used” to such attacks.

“It was only last January that there was the Charlie Hebdo attack... then November the tragedy in Paris, so this is just more of the same,” he said.

Gee said that he doesn’t believe the attack will stop French people from going out to watch fireworks, gathering in bars or standing in solidarity with one another.

With files from The Associated Press