Nice attack: Countries around the world mourn victimsReuters

Islamic State (Isis) has claimed responsibility for the Bastille Day truck attack on the Promenade des Anglais seafront in Nice, which killed 84 people and left more than 200 injured. The terror group made the claim through its propaganda arm, the Amaq News Agency.

Citing a "security source" the terrorist organisation's publicity agency said the attacker, identified as Mohamed Lahouaiej-Bouhlel, "carried out the operation in response to calls to target the citizens of coalition countries fighting the Islamic State".

The statement from Isis (Daesh), distributed through a Telegram account linked to the terror group, did not name Lahouaiej-Bouhel, referring to him as "one of the soldiers of Islamic State". The notice appeared to suggest he had acted alone.

Lahouaiej-Bouhlel was shot dead by police after firing at officers with a pistol, as he drove the 19-tonne lorry through a 30,000-strong crowd, indiscriminately killing and injuring all who got in his way, including 10 children. At least 202 people were injured, of whom 52 are critical with 25 on life support.

French investigators said they found an ammunition magazine, a fake pistol, replica Kalashnikov and M16 rifles and a dummy grenade in the truck's cabin.

Nice prosecutor Francois Molins said Lahouaiej-Bouhlel was a chauffeur and delivery man, known to police as a petty criminal but "totally unknown to intelligence services". He was "never flagged for signs of radicalisation" Molins added.

However, Prime Minister Manuel Valls told France 2 television that Lahouaiej-Bouhlel was a "terrorist without doubt linked to radical Islamism in one way or another".

Islamist terrorist or mass murderer?

Lahouaiej-Bouhlel had three children, but was separated from his wife, who was reportedly divorcing him. She was taken into custody on 15 July.

Police also arrested another man believed to have been linked with Lahouaiej-Bouhlel that day. Three others were held on the morning of 16 July. The arrests, made in two different areas in Nice, targeted the attacker's "close entourage" according to Reuters news agency.

The Paris prosecutors released no additional information about the arrests and it was unclear who was in custody. In the France's legal system, prosecutors lead the initial stages of a police investigation, before handing oversight of the case to an investigating judge.

It has emerged that the 31-year-old "loner" Lahouaiej-Bouhlel consumed alcohol and pork in defiance of Islamic beliefs. He also had a criminal record, which included domestic violence and threatening behaviour during a road rage incident.

A ceremony to pay tribute to the victims, which was to be held in Nice on 16 July, was called off for security reasons according to Le Figaro.