(CNN) -- Eight people are dead and 24 are still unaccounted for after a fire ripped through an elderly community in Quebec on Thursday, officials confirmed Saturday.
Search teams continued to comb ice-covered debris for the missing at the Residence du Havre in the small town of L'Isle-Verten, police said.
Frigid temperatures have made search efforts difficult, as water used to fight the blaze froze, coating the collapsed three-story building in ice.
"The ice in certain areas is as thick as 60 centimeters. We're talking 2 feet," Guy Lapointe, with Surete du Quebec police, said. "So you can imaging how difficult it is to go through the ice, melt it and again do it in a way that we protect the integrity of the potential victims."
Lapointe said it's unlikely any of the missing escaped the fire.
"I think we can all agree here today that the 24 people that are still missing... I think we can assume the worst, but you have to understand that we're not going to confirm any deaths until we have actually recovered the remains," he said.
Heavy equipment to help melt the ice has been brought in, Lapointe said.
The cause of the fire that began early Thursday morning at the complex, where at least 52 people were believed to be living, is still under investigation. A lit cigarette is one of many possibilities authorities are looking into, officials said.
At least 37 were older than 85, according to government documents obtained by CNN affiliate CBC.
Acting Mayor Ginette Caron told CBC that many of the residents had Alzheimer's disease and used wheelchairs or walkers.
Witnesses said they saw a number of residents calling out to firefighters for help from their windows and balconies.
Pascal Fillion, who lives near the complex, told CTV he heard screams coming from inside, but the fire was so intense there was little firefighters could do.
"There was one person we saw, who they wanted to save, but he was on the top floor, and with the fire and the wind they weren't able to come any closer," he said.