Thursday night's attack in the Riviera city of Nice plunged France into new grief and fear just eight months after gunmen killed 130 people in Paris. Those attacks, and one in Brussels four months ago, have shocked Western Europe, already anxious over security challenges from mass immigration, open borders and pockets of Islamist radicalism.
The truck zigzagged along the city's seafront Promenade des Anglais as a fireworks display marking the French national day ended. It careered into families and friends listening to an orchestra or strolling above the Mediterranean beach towards the century-old grand Hotel Negresco.
At least 10 children were among the dead. Of the scores of injured, 25 were on life support, authorities said on Friday.
Witness Franck Sidoli said he had watched people mown down before the truck finally stopped just five meters away from him.
"A woman was there, she lost her son. Her son was on the ground, bleeding," he told Reuters at the scene.
The driver, 31-year-old Mohamed Lahouaiej Bouhlel, shot dead by officers at the scene, was known to police for petty crimes but was not on a watch list of suspected militants. He had one criminal conviction, for road rage, and was sentenced to probation three months ago for throwing a wooden pallet at another driver.
The investigation "will try to determine whether he benefited from accomplices," Paris prosecutor Francois Molins said. "It will also try to find out whether Mohamed Laouaiej Bouhlel had ties to Islamist terrorist organizations."
"Although yesterday's attack has not been claimed, this sort of thing fits in perfectly with calls for murder from such terrorist organizations," Molins added.
Bouhlel's ex-wife was in police custody, Molins said. He had three children. Police found one pistol and various fake weapons in his truck.
French Prime Minister Manuel Valls told the evening news that Bouhlel was "one way or another" linked to radical Islam. "Yes, it is a terrorist act and we shall see what links there are with terrorist organizations."
Yet despite numerous French officials from President Francois Hollande down describing it as a terrorist attack, by nightfall on Friday officials still had not disclosed any direct evidence linking Bouhlel with extremists.
Interior Minister Bernard Cazeneuve acknowledged as much. Asked if he could confirm the attacker's motives were linked to jihadism, he said: "No."
"We have an individual who was not known to intelligence services for activities linked to jihadism."
A US official familiar with Washington's assessment said the attack was thought to have been carried out by a "lone wolf" inspired but not directed by Islamic State.
Dried blood, smashed strollers
Dawn broke on Friday with pavements smeared with dried blood. Smashed children's strollers, an uneaten baguette and other debris were strewn about the promenade. Small areas were screened off and what appeared to be bodies covered in blankets were visible through the gaps.
The truck was still where it had come to rest, its windscreen riddled with bullets.
"I saw this enormous white truck go past at top speed," said Suzy Wargniez, a local woman aged 65 who had watched from a cafe on the promenade. "It was shooting, shooting."
At Nice's Pasteur hospital, medical staff were treating large numbers of injuries. Waiting for friends who were being operated on was 20-year-old Fanny.
"The truck pushed me to the side. When I opened my eyes I saw faces I didn't know and started asking for help," she told Reuters. "Some of my friends were not so lucky. They are having operations as we speak."
Neighbors in the residential neighborhood in northern Nice where Bouhlel lived described him as a handsome man but an unsettling presence.
"I would say he was someone who was pleasing to women," said neighbor Hanan, standing in the lobby of the apartment building where Bouhlel lived. "But he was frightening. He didn't have a frightening face, but ... a look. He would stare at the children a lot."
Bouhlel's Tunisian home town Msaken is about 10 km (six miles) outside the coastal city of Sousse, where a gunman killed 38 people, mostly British holidaymakers, on a beach a year ago. Many people from the area have moved to France, including Nice, and money they send back has made it comparatively prosperous.
A former neighbor in Msaken told Reuters Bouhlel had left for France in 2005 after getting married, and had worked as a driver there.
Relatives and neighbors in Msaken said Bouhlel was sporty and had shown no sign of being radicalised, including when he last returned for the wedding of a sister four years ago.
