The blaze in ​the High Fens, a nature reserve in the east of the country, has been ​burning since Friday, and firefighters from across Belgium and neighbouring Germany and ⁠Luxembourg have sought to contain it, as have the army and farmers.

Responders on Sunday were ​focused on the front line of the fire moving towards Germany and were hopeful that ​cooler, more humid weather would support efforts to contain it, Stephanie Ernoux, spokesperson for the administration of the Belgian region of Wallonia, told Reuters.

The fire is more than double the size of a blaze in ​2011 that burned close to 1,400 hectares, data from the European Forest Fire Information System ​showed.

The German town of Monschau, near the Belgian border, said on Sunday that the fire was not expected ‌spread ⁠to German territory but significant smoke pollution was likely.

“It has therefore been decided to advise residents in the areas close to the border to leave these areas,” a statement on the town website said.

The EU deployed three helicopters and two water bomber aircraft from around Europe ​on Saturday after Belgium ​requested emergency reinforcements.

Local authorities ⁠said the defensive line protecting evacuated villages from the fire was holding on Sunday, though residents who had been evacuated on Saturday were ​told they should not yet return to their homes.

“No homes have ​been affected ⁠at this stage, although the fire remains close and smoke levels are significant,” the office of the governor of Liege said in an update.

The blaze ignited as European countries, including Belgium, suffered ⁠their fifth ​heatwave of the summer this week.

Scientists say that human-caused ​climate change has increased the likelihood of the hot and dry conditions that allow wildfires to spread faster and ​burn longer.