A gunman smashed a truck into a crowd of revelers celebrating Bastille Day in the French resort of Nice, killing at least 84 people in what President Francois Hollande on Friday declared a “terrorist” attack, the third such assault in two years.

Police shot the driver dead after he barreled the truck two kilometers through a crowd that had been enjoying a fireworks display for France’s national day on Thursday night.

The palm-lined Promenade des Anglais of the French Riviera resort was left strewn with bodies as hundreds fled in terror.

The attack on France’s national holiday rocked a nation still dealing with the aftermath of attacks in November in Paris that killed 130 and in January 2015 that killed 17.

“France was struck on the day of its national fete, July 14, the symbol of liberty,” a somber Hollande said on national television early Friday, denouncing “this monstrosity” — a truck bearing down on citizens “with the intention of killing, smashing and massacring … an absolute violence.”

“The terrorist character (of the attack) cannot be denied,” he said. “All of France is under the threat of Islamic terrorists.”

Hollande said it was not immediately clear whether the driver had accomplices. The Paris prosecutor’s office opened an investigation for “murder and attempted murder in an organized group linked to a terrorist enterprise.”

The driver of the truck has been formally identified, police sources said.

He is a 31-year-old Franco-Tunisian man whose identity papers were found in the vehicle after the attack.

Police have not yet released the attacker’s name, but they said he lived in Nice. Other sources said previously he was already known to police for minor criminal offences.

Politicians from around the world reacted with horror after the attack.

U.S. President Barack Obama condemned what he said appeared to be a “horrific terrorist attack.”

“We stand in solidarity and partnership with France, our oldest ally, as they respond to and recover from this attack,” he said in a statement.

“On this Bastille Day, we are reminded of the extraordinary resilience and democratic values that have made France an inspiration to the entire world.”

U.S. Secretary of State John Kerry, who had been in Paris earlier in the day for a Bastille Day parade, said: “The United States will continue to stand firmly with the French people during this time of tragedy. We will provide whatever support is needed.”

Canadian Prime Minister Justin Trudeau wrote on Twitter: “Canadians are shocked by tonight’s attack in Nice. Our sympathy is with the victims, and our solidarity with the French people.”

A spokesman for new British Prime Minister Theresa May called the attack “a terrible incident,” adding “we are shocked and concerned.”

Boris Johnson, whose first engagement as Britain’s new foreign secretary was at the French ambassador’s Bastille Day party in London, said on Twitter: “Shocked and saddened by the appalling events in Nice, and the terrible loss of life.”

The United Nations Security Council called the attack “barbaric and cowardly.”

Germany “stands alongside France in the fight against terrorism,” Chancellor Angela Merkel said, adding that “words can barely express” what France’s allies felt.