A French official on Friday said 10 children were among the 84 people killed when a gunman rammed a truck through a crowd of thousands celebrating Bastille Day on the French Riviera on Thursday evening.

The driver was shot dead by police and no one immediately claimed responsibility for the Thursday night attack on France’s national holiday, which rocked a nation still dealing with the aftermath of two attacks in Paris last year that killed a total of 147 people.

French President Francois Hollande on Friday morning said the rampage was “undeniably” a terror attack.

Police sources said the driver had been formally identified as a 31-year-old Franco-Tunisian man whose identity papers were found in the vehicle after the attack.

Media reports have identified the attacker as Mohamed Lahouaiej Bouhlel.

Other police sources said he was already known to police for minor criminal offenses. A police source said the vehicle had been rented in the region “a few days ago.”

Christian Estrosi, the regional president in Nice, confirmed that 10 children had been killed.

Estrosi said some of the city’s 1,200 security cameras had pinpointed the moment the attacker boarded the truck, far from the beachfront “in the hills of Nice” and could follow his path to the promenade. Estrosi called for the investigation to focus on any accomplices.

“Attacks aren’t prepared alone. Attacks are prepared with accomplices,” Estrosi said. “There is a chain of complicity. I expect it to be unveiled, discovered and kept up to date.”

Estrosi said France needed to think carefully about its next response to attacks, as previous responses were not enough to protect the people.

French Prime Minister Manuel Valls said the government was declaring three days of national mourning. Speaking after an emergency meeting, Valls said the national mourning would begin Saturday.

He confirmed that a measure extending the country’s state of emergency would go before lawmakers next week.

The children’s hospital in Nice said it has treated some 50 children and adolescents injured in the truck attack, including two who died during or after surgery.

Stephanie Simpson, the communications director for the Lenval foundation hospital, told The Associated Press that injuries included fractures and head injuries and that the victims were aged 18 or under.

In a phone interview, she said: “Some are still life-and-death.”

She said she could not say the exact number of children hospitalized or the ages of those who died.

The hospital, equipped with one of France’s largest pediatric emergency units, also called the families of children it was already treating before the attack to ask them to pick up their children to free up rooms for the attack victims.

The truck plowed into the crowd over a distance of two kilometers (about 1.2 miles), a lawmaker said, and broadcast footage showed a scene of horror up and down the promenade, with broken bodies splayed on the asphalt, some piled near one another, others bleeding onto the roadway or twisted into unnatural shapes.

Some tried to escape into the water, said Eric Ciotti — a lawmaker for the region that includes Nice — giving new details on Friday of the horrifying last minutes of the attack.

“A person jumped onto the truck to try to stop it,” Ciotti told Europe 1 radio. “It’s at that moment that the police were able to neutralize this terrorist. I won’t forget the look of this policewoman who intercepted the killer.”

Wassim Bouhlel, a Nice native, told The Associated Press that he saw a truck drive into the crowd. “There was carnage on the road,” he said. “Bodies everywhere.” He said the driver emerged with a gun and started shooting.

A policeman stands, watching the truck used for the attack near the scene of an attack after a truck drove onto the sidewalk late Thursday, and plowed through a crowd of revelers who gathered to watch the fireworks in the French resort city of Nice, southern France, Friday, July 15, 2016. (AP Photo/Luca Bruno)

A policeman investigates the truck the day after it plowed through a crowd of revelers who gathered to watch the fireworks in the French resort city of Nice, southern France, on July 14, 2016. (AP/Luca Bruno)

Leading Muslim clerics joined Gulf Arab states and world leaders on Friday in condemning the attack.

Egypt’s top Muslim cleric Shawki Allam condemned the assailant as an “extremist” who “follows in the footsteps of the devil. Islam never called for the spilling of blood,” Allam said in a statement.

“People who commit such ugly crimes are the corrupt of the earth, and follow in the footsteps of Satan… and are cursed in this life and in the hereafter.”

The six Gulf Arab states issued a joint statement saying that they “strongly” condemned the “terrorist” act in Nice.

“The Gulf Cooperation Council states stand in solidarity with the French republic following this cowardly criminal incident whose perpetrators have been stripped of all moral and human values,” said the bloc’s secretary general, Abdullatif al-Zayani.

Regional heavyweight Saudi Arabia issued its own statement condemning the “heinous terrorist” act, adding that it stands in “solidarity” with France and will “cooperate with it in confronting terrorist acts in all their forms.”

United Arab Emirates Foreign Minister Sheikh Abdullah bin Zayed al-Nahyan said: “This heinous terrorist crime makes it imperative for all to work decisively and without hesitation to counter terrorism in all its forms and manifestations.”

Both Saudi Arabia and the UAE are members of a US-led coalition that has carried out an air war against the Islamic State jihadist group in Syria alongside France. – TIMES OF ISRAEL

PHOTO: AFP