The number of dead or missing after the runaway oil tanker train disaster in a small Canadian town has risen to 60, police announced Wednesday, as the railway chairman headed to the scene.

The confirmed death toll remained at 15, Quebec provincial police inspector Michel Forget told a press conference. The coroner said remains were still being identified.

The list of missing or presumed dead in worst train accident in recent Canadian history rose to 45.

A fire ignited by the crash on Saturday tore through homes and businesses, razing part of Lac-Megantic, a town of 6,000 located east of Montreal near the US border.

The blaze forced about 2,000 residents to flee their homes. Most of them started returning on Tuesday.

The freight train was operated by Montreal, Maine & Atlantic Railway.

It had been stopped for a crew change in the nearby town of Nantes when it began to roll downhill without a conductor towards Lac-Megantic.

It derailed at a curve in the tracks and several cars exploded.

MMA chairman Edward Burkhardt has blamed firefighters in Nantes for the disaster, saying they unwittingly unlocked the train's brakes when they shut down the locomotive's engines to douse a small fire hours earlier.

Burkhardt is likely to face angry residents and questions from police probing for criminal negligence when he arrives in Lac-Megantic to survey the devastation.

Quebec Premier Pauline Marois meanwhile announced Can$60 million (US$57 million) in emergency aid and for reconstruction. "We will do everything we can" to help the victims, she told a press conference.

"This should never have happened," she added.