Fires in Victorian open-cut coal mines have created a major health risk, with hazardous smoke destroying air quality.

The Environment Protection Authority (EPA) issued a high level smoke alert for Morwell South and Morwell East in the Latrobe Valley over the weekend, as potentially deadly amounts of smoke blanketed the region.

EPA readings gave the pollutant-laden air a score of 1,300 on Friday afternoon, with a reading above 150 considered very poor on the Authority’s scale.

The smoke from a fire in the Hazelwood mine has been inundating LaTrobe towns for over two weeks now.

This fire is a particularly stubborn one, as large sections of underground coal catches fire. Authorities say the most effective way to extinguish a sub-surface blaze is to soak the exterior rocks and hope to cool the surrounding area.

EPA's Tanya O'Shea says residents should protect themselves and stay indoors.

“The particles that are of concern health wise,” Ms O’Shea said.

“Visibility is affected, so that's 10 kilometres due to high particle concentration in the air.”

“We urge people to take their precautions, avoid prolonged or heavy physical activity, get inside, bunker down,” she said.

One pharmacy says it has given away over 200 face-masks for free to try to keep locals breathing easily.

“We're offering them to everybody and certainly targeting people who live closer to where the fire is,” says chemist John Bellaby.

The Victorian Government has offered some response, opening a community health assessment centre at the town of Morwell.

At least five schools have been closed, childcare centres as well, with students relocated to safer towns to continue their classes.

The ABC reports that it has evacuated its newsroom in Morwell’s main street.

The Country Fire Authority (CFA) says it is making progress battling the Hazelwood mine fire, but the front still extends over two kilometres along its northern and southern sides.