MARSEILLE, France — The death toll in the collapse of two dilapidated buildings in the southern French city of Marseille rose to six on Wednesday, drawing outrage from residents who say the authorities routinely ignore warnings about the state of housing in low-income neighborhoods.

Rescue workers sifting through the rubble of the adjacent buildings, which crumbled Monday morning in Noailles, near the city’s Old Port, have so far retrieved the bodies of four men and two women, said the Marseille prosecutor, Xavier Tarabeux.

The interior minister, Christophe Castaner, said that 120 police officers and 80 firefighters had joined the search-and-rescue operation, and that they had identified air pockets in the debris that meant there could be survivors.

“We’re working hard, so there’s still hope,” a rescue worker said at dawn on Wednesday as his team, which included sniffer dogs, searched the rubble. No survivors have been found so far.