Jessica Durando

USA TODAY

Paris prosecutor Francois Molins said Thursday the truck driver who killed 84 people on a Nice beachfront last week had accomplices and plotted his attack for months.

Molins said five suspects currently in custody face preliminary terrorism charges for their alleged roles in helping driver Mohamed Bouhlel, who was killed by police, the Associated Press reported.

Four men and a woman were "involved in the preparation" of the attack, and one of the suspects filmed the crime scene the day after the incident, Molins said, according to AFP.

Witness in Nice: 'Bodies flying like bowling pins'

"The investigation underway since the night of July 14 has progressed and not only confirmed the murderous premeditated nature of Mohamed Lahouaiej Bouhlel's act but also established that he benefited from support and accomplices," Molins said at a news conference, CNN reported.

Molins, whose office oversees terrorism investigations, said information from Bouhlel’s cellphone showed searches and photos that suggest he had been studying an attack since 2015, according to the AP.

Images from the scene of the horrific attack in Nice

The Islamic State claimed responsibility for the Bastille Day attack, but investigators have not found any direct ties between Bouhlel and the militant group.

Bouhlel, 31, a Tunisian who lived in Nice for years, drove a truck through the crowd for more than a mile before police shot him. His mobile phone sent a text at 10:27 p.m. the night of the attack that said “bring more weapons, bring him in at 5 C,” according to the French television station BFMTV.

The attack came hours after police removed four vans that had blocked Promenade des Anglais for an earlier military parade to celebrate Bastille Day, according to The Telegraph newspaper in the United Kingdom. Just 60 officers were on duty, despite warnings that Nice was a target of extremists who had visited Syria, according to the newspaper.