Police hunt coal mine arsonist in choking smog

Victoria police are hunting an arsonist who set fire to an open-cut coal mine that has cloaked a nearby town in noxious smog, threatened a major power station and raised fears of a collapse beneath roads and houses.

The fire at Morwell in the LaTrobe Valley, east of Melbourne, has been burning for more than two weeks and at best will take another fortnight to contain.

Police believe the arsonist is a local, who initially set two "test fires" before lighting the main blaze on February 9, Victoria's worst fire day since the 2009 Black Saturday disaster.

Chief Commissioner Ken Lay said the fire had been set with an "absolute disregard for life and property".

"This person took actions that were very, very calculated and designed to create significant damage to the community," Lay said.

On Tuesday the fire came within 500m of the nearby Hazelwood power station, forcing the evacuation of staff before being stopped. Flames reached conveyor belts, causing shutdowns and power supply reductions.

Firefighters trying to contain the blaze along 2km of the mine's northern and southern sides have been forced to use breathing apparatus to counter dangerous levels of carbon monoxide.

Working in round-the-clock shifts of 200, they are being checked regularly for carbon monoxide exposure.

The nearby town of Morwell is cloaked by smog created by smoke and ash from the mine fire and from other bushfires still burning in the surrounding region.

Teams have been doorknocking houses and businesses in the town of 14,000 to check on residents and assess health needs. About 25,000 face masks have been distributed, and several schools and childcare centres have been closed.

Free health checks have been arranged at local medical centres and a respite centre has been set up to help residents escape the smoke for brief periods. Health officials have also advised people to take breaks out of the area.

Although an evacuation plan has been prepared, levels of carbon monoxide in the town so far remain well within safety levels.

"The advice at this stage is there is no need to relocate, that the situation is well within the limits that are applied for heath and safety," Victorian Premier Denis Napthine said yesterday.

But vulnerable residents, including people with chronic heart and lung conditions, asthma, and the very young and aged, have been warned to remain indoors to avoid respiratory problems caused by other particles carried in the smoke.

All residents have been advise to avoid heavy physical exercise.

Hourly updates of particle levels are being posted on the state's Environmental Protection Authority website.

Authorities are also concerned that the fire, which has burned up to 15m into the mine's walls, could also trigger collapses near houses and damage the nearby Princes Freeway, which links Melbourne and Geelong.

Three years ago the freeway was cut after flooding collapsed one of the mine's walls.