The death toll from a devastating fire at a shopping plaza in Pakistan’s largest city, Karachi, rose to at least 23 on Monday as rescue teams recovered more bodies from the severely damaged building, police said, while dozens of people remain unaccounted for.

Firefighters brought the blaze under control late Sunday, nearly 24 hours after it broke out at the multistory plaza, allowing rescuers to begin searching inside. Authorities warned that the number of fatalities could increase as efforts continue to locate 46 missing people, according to Karachi Police Chief Asad Raza.

Raza told The Associated Press that only six of the recovered bodies have been identified so far. Police surgeon Dr Summaiya Sye said the remaining bodies were badly charred and beyond recognition, making DNA testing necessary for identification.

Read More: Death toll rises to 10 in Karachi shopping plaza fire

Earlier, Sindh Chief Minister Murad Ali Shah said rescue teams were continuing operations to find survivors and recover bodies. He confirmed that a firefighter was among those killed and announced that the provincial government would provide compensation of 10 million rupees (about $36,000) to the family of each victim.

Karachi’s Chief Rescue Officer Dr Abid Jalal Sheikh said the fire spread rapidly through shops storing highly flammable materials, including cosmetics, garments and plastic products.

Relatives of the missing gathered outside the gutted building on Monday, anxiously awaiting information. Qaiser Ali said his daughter, daughter-in-law and sister were inside the plaza when the fire broke out on Saturday. He said he remained in contact with them by phone until Sunday, after which communication ceased.

The cause of the fire has not yet been determined. Police said an investigation is underway.