02/03/2014 01:41 EST | Updated 04/05/2014 05:59 EDT

Quebec provincial police raise death toll in seniors' home fire to 28

L'ISLE-VERTE, Que. - Quebec provincial police say they are not ruling out anything — including a criminal cause — in their investigation of a fire at a seniors' home in L'Isle-Verte.

Lt. Guy Lapointe confirmed on Monday that 28 people died when fire roared through the Residence du Havre. Four other people remain missing and are presumed dead.

Provincial police said Monday they have ended recovery operations on the site of the disastrous blaze that struck the seniors' home in the early hours of Jan. 23 and plunged the tiny town into grief.

For more than a week, police, firefighters and coroner's office workers have delicately combed through the debris looking for bodies and evidence to help them determine the cause of the fire.

"The search for both victims and any elements that might allow us to advance the investigation has been concluded," Lapointe said, adding that the investigation is continuing.

"Right now what we're doing is we're still cross-referencing eyewitness accounts, results (of analysis) of items that may have been seized at the scene."

He said police have not ruled out a criminal act.

"It is one of the hypotheses that we're looking at right now but it's not the only one," he said. "We're going to wait until we get the results of the analysis before we know which direction the investigation will be taking."

Lapointe said police had enlisted the aid of a chemist and an electrician in the examination of the evidence at the scene. He would not be specific on what the evidence is for the moment.

Genevieve Guilbault, a spokeswoman for the Quebec coroner's office, said efforts will also continue to identify the remains that have been recovered.

She says the provincial crime laboratory, which is separate from the provincial police, will be aiding in the analysis of the remains, which do not always comprise intact bodies.

"The number of 28 . . . is not definitive and the number of victims recovered may increase following the result of expertise that is carried out," she said.

So far 10 people have been identified.