PARIS: French authorities have arrested four men believed to be linked to the man who killed 84 people when he drove a truck into a Bastille Day crowd in Nice.
One of the men being held was arrested Friday and three others on Saturday morning, a police source added. The death-truck driver's estranged wife is also being held by police.
The arrests came as investigators started to put together a profile of Mohamed Lahouaiej-Bouhlel. They also are tyrying to determine if he had some kind of network that helped him to plan the mayhem he unleashed before police shot him dead.
What they have so far is a picture of a troubled, angry loner with a record of petty crime and domestic violence, but no known connection to terrorist groups.
Islamic State on Saturday claimed that the man who carried out the attack was a "soldier'' of the group but did not name Lahouaiej-Bouhlel.
The veracity of the claim could not be determined, and it appeared at odds with what is known so far about the suspect.
An image obtained from a French police source shows a reproduction of the residence permit of Mohamed Lahouaiej-Bouhlel, the man who rammed his truck into a crowd celebrating Bastille Day in Nice before being shot dead by police. (AFP Photo)
Lahouaiej-Bouhlel, 31, had not been on the radar of French intelligence services before the attack, and was said to have had little interest in religion or Islam.
Lahouaiej-Bouhlel was born in Msaken,Tunisia but moved to France years ago and was living in the country legally, working as a delivery driver.
At an apartment bloc in the Quartier des Abattoirs, on the outskirts of Nice, neighbours described the father of three as a volatile man, prone to drinking and womanising, and in the process of divorcing his wife.
His father said Lahouaiej-Bouhlel had violent episodes during which "he broke everything he found around him".
"Each time he had a crisis, we took him to the doctor who gave him medication,'' Mohamed Mondher Lahouaiej Bouhlel told BFM television.
His son hadn't visited Tunisia in four years and hadn't stayed in contact with his family, he said.
"What I know is that he didn't pray, he didn't go to the mosque, he had no ties to religion,'' said the father, noting that Lahouaiej-Bouhlel did not respect the Islamic fasting rituals during the month of Ramadan.
In a news conference on Friday, hours after the attack in which 84 people were killed and 202 were wounded, prosecutors said they had found no links to the Islamic State extremist group.
Lahouaiej-Bouhlel had had a series of run-ins with the law for threatening behaviour, violence and theft over the past six years. In March, he was given a six-month suspended sentence by a Nice court for a road-rage incident.
His court-appointed lawyer, Corentin Delobel, said he observed "no radicalisation whatsoever", and Paris prosecutor Francois Molins said Bouhlel was never placed on a watch list for radicals.
Still, he could have felt inspired by calls from extremist groups to carry out acts of murder in France, said Molins.
Though no group has claimed responsibility for the Nice attack, President Francois Hollande called it "undeniably terrorist in nature'' and extended a state of emergency imposed after the Nov 13 assault on Paris nightspots that claimed 130 lives.
Records show that the 19-ton truck that was rammed through the seaside crowd in Nice was rented in the outskirts of the city on July 11 and overdue on the night of the attack.
About 25 minutes before the July 14 fireworks show, a popular event that draws hundreds of thousands of people to the seafront each year, Lahouaiej-Bouhlel climbed into the vehicle and drove toward the city center.
Shortly after 10.30pm, he drove onto the Promenade des Anglais that had been closed to traffic for the night.
Witnesses described seeing how Bouhlel purposely steered the truck to hit men, women and children as they tried to flee."
"I saw his face,'' Swedish tourist John Lambert told The Associated Press. "He was totally focused.''
Within minutes the attack was over, with the driver dead in a hail of police gunfire. Inside the driver's cab lay a loaded handgun, three replica firearms and an empty grenade.
Investigators are looking into how Lahouaiej-Bouhlel acquired the cache of weapons. A series of attacks in recent years have shown that radical jihadi networks are seemingly able to obtain guns, and even heavier automatic weapons, with ease in France.
Fellow Tunisians in Nice said they hoped the attack would not reflect badly on them.
"It shocks me because here's a guy who comes from the same town as me,'' said hair stylist Morgan Braham, 31. "Today I'm almost ashamed and afraid. It's not only shame it's also fear, to tell people that we're Tunisian.''
Meanwhile, French security chiefs began a meeting in Paris as Nice's seaside boulevard reopened to traffic on Saturday.
Defence and intelligence leaders gathered at the Elysee Palace, the official residence of the French president, for talks about the atrocity, the third mass casualty attack against France in 18 months.
France is observing three days of national mourning in homage to the victims.