Some 85 people are still in hospital after the attack, 18 of which are in a life-threatening condition. One of those who received text messages was among eight people taken into custody after the attack.
"A search of his computer illustrates a clear ... and recent interest in radical jihadism", Molins said, adding that Bouhlel had recently grown a beard and told people it was for religious reasons.
The attacker was later identified as Mohamed Bouhlel, a 31-year-old man of Tunisian origin who had been a career criminal before becoming rapidly radicalised.
Records show that the 21-ton truck that was rammed through the seaside crowd in Nice was rented in the outskirts of the city on July 11 and was overdue on the night of the attack. Moreover, the Security Council said it was too early to know the real connection between Bouhlel and ISIS, but that it is urgent for the Member States to fight terrorism using every resource under global legislation.
The security official said Bouhlel sold his auto just before the attack, which appeared premeditated. "(Bouhlel) wasn't really a soldier of God who went to Syria and came back to France", Padovani said.
"It seems he was radicalized very quickly", he said.
Neighbors described the attacker as volatile, prone to drinking and womanizing and in the process of getting a divorce. As well, Walid Hamou, a friend of Bouhlel's ex-wife said: "he was no muslin" since he drank a lot, he hit his wife and children when they were too little to walk, and he didn't fast in Ramadan.
"The man behind the running-over operation in Nice, France, is a soldier from the Islamic State, and he carried out the attack to answer the calls for targeting the nationals of countries in the coalition that is fighting Islamic State", said a statement from a social media account linked to the Amaq News Agency, which bills itself as the terrorist network's semi-official news outlet. Memorials have been set up on the westbound lane of the road where victims were struck, some still identifiable by bloodstains. Some areas are still stained by blood.
Joggers, bikers and sunbathers cruised down the pedestrian walkway along the glistening Mediterranean Sea on Sunday, where well-wishers placed flowers, French flags, stuffed animals and candles for the victims.
Within minutes the attack was over, with Bouhlel dead in a hail of police gunfire.
A woman asked if she could put a yellow potted plant there, unaware of the significance of the spot. A man standing nearby said "Never here". An argument ensued, with other passers-by saying that his family deserved respect.
'Social services were concerned about what he was doing to the youngsters, and wanted to keep him away from them, ' said an investigating source.
Many families are angry that they couldn't find information about missing loved ones. Surveillance footage shows him in the truck he used to carry out the carnage, he said.
He also took a selfie at the wheel of the truck in the days before the attack.
The dead included six of seven members of one extended family - three generations - from northeastern France who had gathered in Nice to celebrate Bastille Day and each other's company.
Valls, in the newspaper interview, defended the government's actions but warned that more lives will be lost to this kind of violence.
He said on Friday: "Times have changed and we should learn to live with terrorism".