Crews have recovered the remains of six people from the debris of the apartment block, which was destroyed in the early hours of Sunday after an explosion which may have been caused by a gas leak.

“The toll is unchanged and operations are continuing,” a fire service spokesman told AFP on the scene early on Tuesday.

Five women and three men were believed to have been in the building when it fell.

Four of the dead have been identified, a husband and wife both aged 74 and two more women aged 65 and 88, Marseille prosecutor Dominique Laurens told reporters Tuesday.

“The search is getting more and more dangerous,” she said.

“Ruins have to be combed by hand” because of the “very great danger to the stability” of a neighbouring building.

But eyes are now turning to possible causes for the blast.

“We are working on the hypothesis of a gas explosion,” Laurens said, without ruling out other possible causes as dozens of investigators worked at the scene.

Around 200 people evacuated from the neighbourhood face an uncertain wait before they are allowed to return to their homes.

One building adjoining the fallen block largely collapsed a few hours later, while the structure on the other side was weakened and risks falling in turn.

Other houses on the street may have suffered less visible damage, meaning they have to be torn down, Marseille’s deputy mayor for security, Yannick Ohanessian, said on Monday.

Some residents were allowed to return briefly on Tuesday to recover vital items from their homes, given just a few minutes to choose between important papers, clothes, medicines or a bicycle for the daily commute.

“The worst thing is not knowing how long it’s going to be. I’m most worried not to know where I’ll be living, whether I’ll need to find a new apartment,” said Alhil Villalba, 33.

(AFP)