A wildfire is seen from a police helicopter near the city of Beelitz, Germany. Picture: Polizei Brandenburg/Handout via Reuters

Berlin - Record heat waves and widespread droughts have left their scars this summer - from massive wildfires across Siberia to devastating blazes in Greece that left at least 83 people dead. In Germany, firefighters are now encountering a new challenge: WWII-era ammunition being set off by the flames.

Firefighters used a tank to tackle a blaze near Berlin, as fears over WWII ammunition explosions mounted. Tens of thousands of unexploded bombs and other types of ammunition are still hidden beneath cities and in forests across the country, which regularly results in evacuations as specialists work to defuse the still-lethal war remnants.

Defusing WWII ammunition is not an option when a blaze is raging right around them, however.

"We've received some information that there have been a number of detonations," said Raimund Engel, a representative for the German federal state of Brandenburg's firefighting authorities. The munitions may also have triggered the fire in the first place.

To protect nearby villages, officials set up a more than half-mile police cordon and moved into the forest with a firefighting-tank. By Friday, the fire appeared to be under control.

In Sweden, meanwhile, authorities on Thursday opted for the unusual measure of using bombs themselves. Aiming to cause a lack of oxygen in the wildfire's centre, the country's military used a fighter jet to drop explosives on a forest stretch near the county of Dalarna. Officials acknowledged that the method was only used as a last-resort measure for what they called a "worst-case scenario."

"Our preliminary assessment is that it has had a very good effect," a Swedish official said.

Germany's coordinated response indicated the experience authorities have in dealing with unexploded war munitions that almost regularly shuts down vital infrastructure routes or entire cities.

One construction worker died in the city of Euskirchen six years ago when he dug into a World War II explosive without noticing it. In June 2010, three bomb disposal workers were killed when a bomb they were trying to defuse in the German city of Göttingen suddenly exploded.

In April, Germany's main railway station in Berlin was closed as a nearby 1 000-pound, British-made bomb WWII bomb had to be defused - one of approximately 50 000 that were dropped by the Allied forces. A fifth of those bombs are believed to have never detonated. Many remain hidden unless construction works - or forest fires - finally uncover their locations.

The Washington Post