The Interior Minister said "numerous" other people have sustained injuries, but a specific number has not been released.
Shortly after 10:30 p.m. local time, a long white truck drove into a crowd that had gathered on the Promenade des Anglais to watch Bastille Day fireworks. Eyewitnesses told French television station BFMTV that they heard gunfire, and photos show the windshield of the truck involved in the crash is riddled with bullets.
The driver was shooting out the window as he rammed through the crowd, said Christian Estrosi, president of the regional government. Estrosi also said the attack appeared to be "completely premeditated behavior" and the truck was "loaded with arms, loaded with grenades."
The driver of the truck was killed by French police.
Officials have stated the attack was deliberate but have not yet said whether it is a terrorist attack or whether it is linked to ISIS or other foreign terrorist organizations.
Jimmy Ghazal, 39, of Lebanon is visiting Nice with his family and was at the promenade with his wife and two children at the time of the attack. He told ABC News the Bastille Day celebration was ongoing but the fireworks were over when the truck plowed into the crowded pedestrian area. Ghazal said he heard loud noises, screams and shots fired, and that everyone around him started to run and take shelter.
"I saw a big truck driving through. The truck drove through all the security," he told ABC News.
Ghazal said his family is okay and his children did not see anything.
"The kids thought it was part of the fireworks. We just told them it was part of the fireworks," he said.
Wassim Bouhlel, a Nice native who spoke to the Associated Press near Nice's Promenade du Paillon, said he saw a truck drive into the crowd and then witnessed the man emerge with a gun and start shooting.
The local government has implemented its protocol for a terrorist attack. French police are asking citizens not to leave the house and to stay calm.
Earlier Thursday, Hollande said France's state of emergency, which has been in place since the Paris terror attacks, would be lifted later in July. He is meeting with members of his cabinet at this time.
The American Embassy in France says it is working to determine if any U.S. citizens were killed or injured in the attack.
President Obama condemned what he says "appears to be a horrific terrorist attack" in Nice.
Obama said, "Our thoughts and prayers are with the families and other loved-ones of those killed."
Noting that the attack occurred on Bastille Day, Obama praised "the extraordinary resilience and democratic values that have made France an inspiration to the entire world."
Obama is offering French officials "any assistance that they may need to investigate this attack and bring those responsible to justice."
France's ambassador to the United States, Gerard Araud, characterized the events in Nice as a "terrorist attack."
"Our democracies - France, the United States, our other partners, we are besieged, we face a terrible threat," Araud said at a Bastille Day reception at the French Embassy in Washington late Thursday.
Donald Trump tweeted that in light of the attack, he will postpone his news conference scheduled for Friday to announce his vice presidential pick will be postponed.
In light of the horrible attack in Nice, France, I have postponed tomorrow's news conference concerning my Vice Presidential announcement.— Donald J. Trump (@realDonaldTrump) July 14, 2016
News of the attack in Nice reached revelers at a Chicago Bastille Day Celebration as it began at Montrose Beach around 5:30 p.m. Already slated to attend the festivities, Consul General of France in Chicago Vincent Floreani offered his condolences in English and French.
"I would like all of you to have a thought for the victims and the families of the victims, of the people who were killed today in Nice," Floreani said.
The attack weighs heavily on the hearts and minds of Chicagoans with deep ties to the region. Emilie Roman lives about 45 minutes away from Nice, and was at Montrose Beach when she found out about the attack.
"I have been trying to contact my family because originally I live 45 minutes from Nice, just to make sure no one was there for the celebration for the 14th of July," she said.
"I pray for my friend, for my family, every people," said Sonny Nourad, also originally from the area near Nice.
Juan-Luis Goujon, president of the French American Chamber of Commerce in Chicago, also weighed in on yet another attack on French soil.
"It is happening everywhere, no one is immune to hate. Violence is something we are living with," said Goujon.
Chicago police say they are monitoring the situation in France and are in contact with federal partners, but there is no homeland security threat. Chicago and Chicago police remain in an elevated security state due to the shooting in Dallas last week and the security measures put in place following that attack remain in place.
At O'Hare Airport Thursday night Juan Salas, who arrived in Chicago on a flight from Nice, said his friend was there when the attack happened.
"There was a lot of shooting," Salas said.
My thoughts are with the people of France tonight after another horrific terror attack. America stands with you— Senator Dick Durbin (@SenatorDurbin) July 14, 2016