Belgium is battling its largest wildfire on record, with the blaze scorching around 3,000 hectares and spreading toward the German border, according to local officials.

The fire broke out on Friday in the High Fens nature reserve in eastern Belgium and remained out of control on Monday despite cooler weather and overnight rain.

Around 500 firefighters have been deployed, supported by the military, farmers, and aircraft sent from several European countries. Germany, Luxembourg and the Netherlands have also assisted the operation, while Belgium activated the EU Civil Protection Mechanism.

The blaze has already burned more than twice the area destroyed by Belgium’s previous record fire in 2011, according to European Forest Fire Information System data.

Authorities said the fire was moving toward the German town of Monschau, around 8km from the affected area. Residents near the border have been advised to leave as a precaution, primarily because of heavy smoke.

The difficult terrain has complicated firefighting efforts, with some areas inaccessible to ground crews. Officials have also warned that flames could continue smoldering underground in the region’s peat soil for weeks or even months before flaring up again.

Europe has been hit by a severe wildfire season following repeated heatwaves and prolonged dry conditions. Two people were killed by fires on the Greek island of Salamina on Sunday, while major blazes have also swept parts of France and Spain.

Firefighting efforts elsewhere have also been complicated by EU sanctions on Russia. Spain has been left unable to use its former fleet of Russian-made Kamov Ka-32 helicopters, which are considered especially effective in difficult wildfire conditions due to their high water-carrying capacity and maneuverability.

EU restrictions have blocked access to spare parts and Russian maintenance specialists to service the helicopters, forcing the Spanish authorities to rely on less effective replacement aircraft.