Islamic State (IS) has claimed responsibility for the attack in the French coastal city of Nice, which claimed the lives of at least 84 people and left around fifty other critically injured on Thursday evening.

Amaq Agency, a news agency linked to the militant group, announced that the attack was carried out by IS follower, who responded to a call to target the citizens of the countries participating in the coalition against IS, the BBC informs.

A lorry rammed into the crowds who had gathered at the popular Promenade des Anglais to celebrate the national holiday of France – Bastille Day and observe the traditional fireworks.

The perpetrator, who has been identified as 31-year-old man of French-Tunisian origin, drove for two kilometres through the crowd, before being shot dead by security forces.

The driver reportedly swerved the vehicle from side to side to his as many people as possible.

Mohamed Lahouaiej Bouhlel, whose identity documents were found in the lorry, was known to police, but was not suspected of affiliation with jihadist organisations.

French authorities have classified the attack as being of terrorist nature and have extended the state of emergency, which has been in place since last year's November 13 attacks, by three months.

IS had also claimed responsibility for the multiple gun and bomb attacks in the French capital which claimed the lives of 130 people and left hundreds other injured.

Meanwhile,  four men suspected of being in close ties with the Nice attacker have been detained. One of them was arrested on Friday and the three others were detained on Saturday.