Eight people are not responding to calls and are thought to be under the rubble of two buildings that collapsed in an explosion early on Sunday in Marseille, local officials said. The cause of the explosion in the southern French city was not yet known, Marseille prosecutor Dominique Laurens said. The collapse caused a fire that has complicated rescue efforts and investigations, and it has not yet been brought under control, she told a news conference on Sunday evening. Television footage showed clouds of smoke rising from the rubble as firefighters tried to put out the fire, while trained dogs were used to try to locate victims. “We have nothing, not even an ID card. We have lost everything,” said a man who gave his name as Roland in an interview with local newspaper La Provence. He managed to get out of the building on 15 Rue de Tivoli with his wife and two children before it collapsed, together with a neighbouring building. A third building partly collapsed. Five people were taken to hospital with serious but not life-threatening injuries. The interior minister, Gérald Darmanin, who visited the site, said 30 buildings in the area were evacuated. “I was sleeping and there was this huge blast that really shook the room. I was shocked awake as if I had been dreaming,” said Saveria Mosnier, who lives in a street near the site in the La Plaine neighbourhood. “We very quickly smelled a strong gas odour that hung around. We could still smell it this morning,” she added. It is unclear how many people were inside the collapsed buildings . “Not all the people who were supposedly inside … have been seen. Families are worried,” the French housing minister, Olivier Klein, told the broadcaster Franceinfo. “We have to be very cautious about what the cause was at this stage,” said Christophe Mirmand, the prefect of the southern Bouches-du-Rhône region. Gas was “one possible option”, he said. Gilles, who lives on a sidestreet near the building, told AFP the sound of the crash “was huge”. “It sounded like an explosion,” he said, declining to provide his last name. Eight were killed in Marseille in 2018 when two dilapidated buildings in the working-class district of Noailles caved in. It cast a harsh light on the city’s housing standards, with aid groups saying 40,000 people live in shoddy structures. But authorities appeared to rule out structural issues in the latest collapse, in a neighbourhood known for its bars and nightlife. “There was no danger notice for this building, and it is not in a neighbourhood identified as having substandard housing,” said Mirmand. Further back in Marseille’s history, eight people were killed in a building collapse in 1981, five in an explosion in 1985, and four in a 1996 gas blast that demolished a seven-storey building.