The massacre in Nice has prompted questions over security and intelligence failings after the third major attack in France in 18 months
Nice (France) (AFP) - The Islamic State group claimed responsibility Saturday for the truck massacre in Nice, as France highlighted the "extreme difficulty" of preventing such attacks amid tough questions over security failures.
In a statement via its Amaq news service, IS said one of its "soldiers" carried out the attack "in response to calls to target nations of coalition states that are fighting (IS)".
Tunisian Mohamed Lahouaiej-Bouhlel, 31, on Thursday night ploughed a 19-tonne truck into a crowd of people who had been watching Bastille Day fireworks in the French Riviera city, killing 84 and injuring around 300.
After crisis talks in Paris, French Defence Minister Jean-Yves Le Drian noted that IS had recently repeated calls for supporters to "directly attack the French, Americans, wherever they are and by whatever means".
"Even when Daesh is not the organiser, Daesh breathes life into the terrorist spirit that we are fighting," he said, using an Arabic name for IS.
In the wake of its third major terror attack in 18 months, the French government faced searing criticism from opposition politicians and newspapers demanding more than "the same old solemn declarations".
Marine Le Pen, the far-right leader of the National Front party, called on Interior Minister Bernard Cazeneuve to step down.
"In any other country in the world, a minister with a toll as horrendous as Bernard Cazeneuve -- 250 dead in 18 months -- would have quit," she said.
Cazeneuve defended France's security efforts, saying the country was facing "a new kind of attack" which highlighted "the extreme difficulty of the anti-terrorism fight".
Speaking as France began three days of mourning on Saturday, he said Lahouaiej-Bouhlel "had not been known to the intelligence services because he did not stand out... by being linked with radical Islamic ideology".
The interior minister pledged to boost the presence of security forces across the country and called on willing "French patriots" to join the country's operational reservists -- currently made up of 12,000 volunteers.
Police said Saturday they had arrested four more people linked to Lahouaiej-Bouhlel, in addition to his estranged wife who was taken into custody on Friday.
Cazeneuve said the father-of-three "seemed to have been radicalised very quickly, from what his friends and family" have told police.
"We are now confronted with individuals open to IS's message to engage in extremely violent actions without necessarily having been trained or having the weapons to carry out a mass (casualty) attack."
- 'Where is my son?' -
At least 10 children and adolescents were among the dead as well as tourists from the United States, Russia, Ukraine, Switzerland and Germany.
A spokeswoman for the Nice paediatric hospital said 16 bodies had not yet been identified.
The French health ministry said five children and 21 adults were still fighting for their lives in a critical condition in hospital and were among 121 people still hospitalised.
Tahar Mejri is one of 30,000 people who had gone to watch the fireworks on the palm tree-lined Promenade des Anglais when their night turned to horror as the truck left mangled bodies strewn in its wake.
He lost his wife in the attack and was hunting Saturday for his four-year-old son.
"I have called everywhere, police stations, hospitals, Facebook and I can't find my son. I have been looking for him for 48 hours," he told AFP.
"My wife is dead, where is my son?"
Hours later, he emerged wailing in distress from the Pasteur Hospital in the north of Nice after learning that his son was also dead.
IS also claimed responsibility for the November 13 attacks which killed 130 people in Paris, while gunmen in January 2015 attacks on the Charlie Hebdo weekly and a Jewish supermarket were linked to both IS and Al-Qaeda.
A French parliamentary inquiry last week criticised numerous failings by the intelligence services over the Paris attacks.
France is also home to hundreds of jihadists who have flocked to fight alongside IS.
- 'A wall of cement' -
Cazeneuve also defended the security measures taken for the celebrations of France's national day.
He said police cars were unable to follow the truck onto the seaside walkway after it had "violently forced through the barriers" and onto the sidewalk.
Anthony Borre, director of the Nice mayor's office, said the truck had "pulverised" the barriers at a speed of 90 kilometres (56 miles) per hour.
The truck zigzagged for two kilometres (1.2 miles) through the crowd before police bullets killed the driver and brought an end to the carnage.
"You would have needed a wall of cement to stop him," he said.
Neighbours described the attacker, who worked as a delivery man, as a loner who never responded to their greetings, and who had been violent towards his estranged wife.
Lahouaiej-Bouhlel's father said he had suffered from depression and had "no links" to religion.
"From 2002 to 2004, he had problems that caused a nervous breakdown. He would become angry and he shouted... he would break anything he saw in front of him," Mohamed Mondher Lahouaiej-Bouhlel said in Tunisia.