Wildfires have been burning through the forest in Älvdalen, central Sweden for 13 days.

To make matters worse, the blaze is in a target-practice area which contains undetonated shells. This has made it difficult for firefighters to get safe access to the fire on the ground, and other options have so far proved fruitless.

At noon on Wednesday the Armed Forces dispatched two Jas 39 Gripen fighter jets to drop a bomb on the flames as a last resort, with the hope that the pressure from the blast would help contain the blaze.

"The oxygen from the fire can be removed with the help of a bomb and in this case it was possible to try it, because the fire is at a firing range," said fire and rescue team leader Johan Szymanski in a statement.

"Our preliminary assessment right now is that this had a good effect."

The bomb, model GBU-49 according to Swedish tabloid Aftonbladet, was dropped from 3,000 metres reaching speeds of 550 km/h before hitting its target with metre precision.

It managed to extinguish fires up to 100 metres from the target, according to initial reports.

READ ALSO: The latest on the wildfire situation in Sweden

Watch the video below (courtesy of the Swedish Armed Forces, subtitles by The Local):

More than 40 wildfires were burning across Sweden at 3pm on Wednesday and more and more counties have enforced total fire bans, making it illegal to have barbecues even in private gardens.

On Monday authorities said an area of 25,000 hectares was burning, including 2,500 hectares in Dalarna, 8,500 in Gävleborg, 500 in Västernorrland and 8,500 in Jämtland.

This is significantly larger than the 14,000 hectares that burned in a 2014 fire in Västmanland, which at the time was Sweden's most serious wildfire in 40 years.

Sweden, where usual summer temperatures are closer to 23C, is under-equipped to deal with this kind of crisis and has been getting help from several other EU and EEA countries.