Nice attack
Nice attackReuters

Sympathisers of the Islamic State group have flooded social media with posts celebrating the deadly attack in the city of Nice in France that claimed the lives of at least 84 people and injured over 100 after a truck ran over crowds who were watching a fireworks display along the Promenade des Anglais seafront on Bastille Day.

"The number of those killed had reached 62 french crusaders and sinful infidels in Nice, France.. God is great, God is great," a tweet read, according to a report by Reuters.

"Oh France, you and the all Europe will never be secure until we will live secure on every inch in the land of the Caliphate," an Isis supporter, whose account has been suspended, wrote on Twitter, according to a report by Vocativ.

"This is the beginning of the attack to take the holy revenge for the killing of Abu Omar Shishani, may Allah accept him," another sympathiser wrote on the Isis al-Minbar forum following the attack.

No one has claimed responsibility for the attack, but supporters of the terrorist group celebrated the horrific mass killing. There was also a post asking all Isis supporters to hijack Nice hashtags, India Today reported.

The truck driver drove for more than 100 metres at high speed before ramming into the crowd. However, he was shot dead, sub-prefect Sebastien Humbert was quoted by Reuters as saying citing France Infos radio, while adding that it was a criminal attack. The driver has not been identified yet.

Rescue operations are being carried out and residents have been requested to stay indoors.

The French authorities, including President Francois Hollande, consider this a terrorist attack. "The terrorist nature of this attack cannot be denied... France as a whole is under threat of Islamist terrorism...this is an absolute horror," Hollande was quoted by India Today as saying.

A statement had been issued by Isis spokesperson Abu Mohammed al-Adnani in September 2014 urging Isis supporters to carry out attacks using vehicles on "disbelieving" Westerners.

"If you can kill a disbelieving American or European — especially the spiteful and filthy French — or an Australian, or a Canadian, or any other disbeliever from the disbelievers waging war, including the citizens of the countries that entered into a coalition against the Islamic State, then rely upon Allah, and kill him in any manner or way, however it may be," Adnani was quoted by Vocativ as saying.

Isis militants had attacked the headquarters of the Charlie Hebdo magazine in Paris leaving 130 people dead in November 2015.