According to Canadian police, 28 bodies have now been found following the train disaster in the Quebec town of Lac-Megantic.
Another 22 people are missing and presumed dead after the train carrying oil derailed and exploded in the town.
Meanwhile, a candlelight vigil scheduled for Friday evening was cancelled due to police concerns over large crowds.
Investigations are continuing into the cause of blast, which saw some 2,000 residents forced to flee their homes.
The town centre – where large areas have been wiped out – is being treated as a crime scene.
Saturday will mark one week since the disaster.
The train, carrying 72 cars of crude oil, was parked shortly before midnight on Friday in the town of Nantes about 7 miles away.
It later rolled downhill, gathering speed until it derailed in Lac-Megantic and exploded.
Officers working in the disaster zone have had “a great deal of difficulty” because of strong petrol fumes, Quebec provincial police spokesman Michel Forget said.
Police say they have identified eight of the recovered bodies.
Investigations are continuing into the cause of Lac-Megantic train blast, which saw some 2,000 residents forced to flee their homes
One has been named as 93-year-old Elianne Parenteau.
Mourners laid flowers and tributes in memory of those killed at a church near the crash site on Friday.
The town’s mayor cancelled the first vigil planned, saying it would overwhelm the town.
“Our capacity to welcome visitors is really saturated,” Mayor Colette Roy-Laroche said.
“We are still in an emergency situation.”
Other vigils are being held across Quebec, including in Montreal, Gatineau and Trois-Rivieres.
Quebec Premier Pauline Marois visited Lac-Megantic on Thursday, and criticized the rail company’s response to the crash.
She said Rail World chief executive Edward Burkhart’s attitude was “unacceptable” and “deplorable”.
She also announced a C$60 million ($57 million) fund to help victims and rebuild the town.
Edward Burkhardt revealed on Wednesday that an engineer who was in charge of driving the train had been suspended without pay, after being accused of failing to set a series of hand brakes.
“I understand the extreme anger,” he said.
“We owe an abject apology to the people in this town.”
Authorities have asked the relatives of those still missing to provide DNA samples.
Officials have also warned that some of the bodies may have been burnt to ashes in the explosion.
Canadian authorities have launched a criminal inquiry into the derailment of an oil train that killed at least 15 people in the small Quebec town of Lac Megantic on Saturday.
Quebec police inspector Michel Forget said investigators had found evidence leading them toward a criminal probe.
The runaway train derailed in the town of Lac-Megantic, exploding and destroying dozens of buildings.
Investigators are focusing on whether the brakes were released as it was parked in a town several miles away.
Inspector Michel Forget said investigators had ruled out terrorism as a motive for the attack but that several other options, including criminal negligence, remained under consideration.
He warned it could take time before the investigation findings emerge.
“This is an enormous task ahead of us,” the police inspector said.
“We’re not at the stage of arrests.”
In addition to the dead, as many as 35 others remain unaccounted for. Authorities have asked the relatives of the missing to provide DNA samples by bringing in toothbrushes, hairbrushes, razors and other items.
But the authorities have also warned some of the bodies may have been burnt to ashes in the explosion and may never be recovered.
On Wednesday, the chief executive of the train’s US owner, Rail World, was due to visit Lac-Megantic, where he could face a hostile reception.
Canadian authorities have launched a criminal inquiry into the Lac Megantic train derailment
In media interviews Edward Burkhardt said he thought he would have to wear a bullet-proof vest when he arrived in the town.
The train, carrying 72 cars of crude oil, was parked shortly before midnight on Friday in the town of Nantes about seven miles away.
An engineer apparently left the train with four of its five locomotives shut down, but kept the final one running to ensure the brakes were engaged.
Soon, a Nantes fire crew was summoned to put out a blaze on the train.
The train’s brakes appear to have failed soon after. It began moving downhill on the track in an 18-minute journey, gathering speed until it derailed in Lac-Megantic and exploded.
“The extent to which [the fire] played into the sequences of events is a focal point of our investigation,” Transportation Safety Board investigator Donald Ross said.
Nantes Fire Chief Patrick Lambert said that his crews had shut down the final locomotive while tackling the initial blaze.
He said this was the standard operating procedure agreed with the train company, Montreal, Maine & Atlantic Railway (MMA), which is owned by Rail World.
“The people from MMA told us, <<That’s great – the train is secure, there’s no more fire, there’s nothing anymore, there’s no more danger>>,” the fire chief said.
“We were given our leave, and we left.”
But MMA says the decision to shut off the locomotive to put out the fire could have disabled the brakes.
At least 30 buildings were destroyed by the fireball that resulted from Saturday morning’s explosion, including a store and the public library.
But the entire town centre is being treated as a crime scene, with several additional streets cordoned off by police tape.
Some 200 officers were still conducting search operations on Wednesday morning. But police said the effort was taking a toll on some crewmen and two people had to be taken off the search over worries for their physical condition.
“This is a very risky environment,” said Quebec Provincial Police Sgt Benoit Richard.
“We have to secure the safety of those working there. We have some hotspots on the scene. There is some gas.”
Maude Verrault, a waitress at the Musi-Cafe, a nightspot razed by the blast, was outside smoking when she spotted the runaway train.
“I’ve never seen a train moving so fast in my life, and I saw flames,” she told the Associated Press news agency.
“Then someone screamed, <<the train is going to derail!>>. And that’s when I ran.”
The train was carrying oil from the Bakken oil region in the US state of North Dakota, taking it to a refinery on the east coast of Canada.
A freight train carrying petrochemicals has exploded in Canadian town Lac-Megantic, forcing the evacuation of up to 1,000 people.
The blast sent a fireball and black smoke into the air, destroying dozens of buildings in Lac-Megantic, some 155 miles east of Montreal.
The train derailed early on Saturday; emergency services who worked through the night said they could not tell if there were any casualties.
Firefighters from across the border in the US are helping tackle the blaze.
A freight train carrying petrochemicals has exploded in Canadian town Lac-Megantic, forcing the evacuation of up to 1,000 people
The train had 70 cars filled with petroleum products, some of which exploded, prompting fires in nearby homes.
It is not clear what caused the explosion.
Some of the train’s cargo spilled into the nearby Chaudiere river, said Environment Quebec spokesman Christian Blanchette.
The train was reportedly destined for Maine.
Lac-Megantic, a lakeside town close to the border with Maine and Vermont, is home to some 6,000 people.