Five people died after a train carrying crude oil derailed and exploded in an eastern Quebec town, with around 40 people still missing.
Authorities in Lac-Megantic feared they could find more bodies once they reached the hardest-hit areas.
Quebec provincial police Lt Michel Brunet said that about 40 people have been reported missing, but cautioned that the number could change.
"We met many people who had reported family members missing. Right now I can tell you about 40," Mr Brunet said. He confirmed two more deaths early on Sunday afternoon after confirming two people were found dead overnight. One death was confirmed on Saturday.
Fires are preventing rescuers from reaching part of the 73-car train, and billowing black smoke could still be seen long after the derailment.
The eruptions early on Saturday morning sent residents of Lac-Megantic scrambling through the streets under the intense heat of towering fireballs and a red glow that illuminated the night sky.
Local Fire Chief Denis Lauzon likened the charred scene to "a war zone". Mayor Colette Roy-Laroche said: "This is really terrible. Our community is grieving and it is taking its toll on us."
The search for victims in the charred debris was hampered because several tanker cars were still burning on Sunday morning, sparking fears of more potentially fatal blasts.
Two of the five cars that exploded are still on fire 36 hours later, Mr Lauzon said. He added that firefighters are staying 500ft from the burning tankers, which are being doused with water and foam to keep them from overheating and exploding. He said: "It's a mess."
The multiple blasts came over a span of several hours in the town of 6,000, which is about 155 miles east of Montreal and about 10 miles west of the Maine border. About 30 buildings were destroyed after tanker cars laden with oil caught fire in the picturesque lakeside town in Quebec's Eastern Townships.