(New throughout, adds temperatures rising, memorial service Sunday, Quebec premier's arrival, Red Cross fund-raising)
By Matthieu Belanger
L'ISLE-VERTE, Quebec, Jan 25 (Reuters) - Thirty-two people were presumed to have died in the fire that swept through a wooden retirement residence in the eastern Canadian province of Quebec on Thursday, police said on Saturday. Eight bodies have been recovered.
The grim reality set in after careful investigation of who was missing and who may have been out of town, and as security officials worked to melt layers of ice up to two feet (60 cm) thick that encased many of the bodies.
"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've actually recovered the remains," police spokesman Guy Lapointe told a news conference.
The fire erupted in the early hours of Thursday and ripped through the Residence Du Havre in L'Isle-Verte, the tiny town northeast of Quebec City that has been devastated by the tragedy.
Teams of firefighters, police and coroner's officials had to use steam machines to melt the ice, caused by the vast amounts of water that was used to put out the flames.
The temperature, which had hovered around minus 22 Celsius (minus 8 Fahrenheit) on Thursday, rose to minus 7 C on Saturday. It was due to drop to minus 17 C on Sunday, according to the federal environment ministry's website.
"You can imagine how difficult it is to go through the ice, melt it, and again, do it in a way that preserves the integrity of potential victims," Lapointe said.
"So it's very difficult work again today. It's very cold. So we're doing our best really to go as fast as possible. Every effort is being deployed. It's just very difficult," he said.
A memorial service will be held in the town on Sunday at 2 pm (1900 GMT). Quebec Premier Pauline Marois has cut short a visit to Europe and plans to be present, officials said.
In the aftermath of the disaster, attention has focused on the fact that only part of the residence was equipped with sprinklers, and that provincial law did not require a sprinkler system there.
Lapointe declined to comment on media reports that the fire may have been caused by a cigarette in a resident's room.
The police are looking into a report that a night guard at the home saw thick smoke coming from a second-floor room.
"Our position right now is that's one hypothesis. There are many that are still on the table. This one is not being privileged at this time, in the sense that it's the same level as the other ones," Lapointe said.
"We're still interviewing people, and we can't just go on one or two facts to state the cause of something of this magnitude."
He also urged residents not to talk to the media, in order to help maintain the integrity of the police investigation.
"Sadly, when people go forward and talk to the media - and I'm not saying it's your fault, not at all - but obviously rumors will start and people come to conclusions, and for us it's very important that we do the job thoroughly and come to the right conclusion at the end," he told reporters.
The Quebec branch of the Red Cross, which on Friday appealed for C$200,000 ($180,200) to help those affected by the disaster, said it had already raised the entire sum.
Much of the money will be spent on items such as wheelchairs, clothing, small items of furniture, dentures, hearing aids and eye glasses, Red Cross spokesman Pascal Mathieu told a news conference on Saturday.
Some of the specialized hearing aids which are needed can cost up to C$5,000 per person, he said.
($1=$1.11 Canadian) (Writing by Randall Palmer and David Ljunggren; Editing by Jeffrey Hodgson, Gunna Dickson and David Gregorio)