Aerial support began assisting firefighters on Sunday in their effort to bring Belgium's largest wildfire in modern history under control, after the blaze grew rapidly since first breaking out two days earlier in a hard-to-access nature reserve.
More than 250 firefighters and emergency workers were battling to contain the blaze in the High Fens park near the German border, an area of fragile peatlands and pine forests popular with hikers.
Authorities described the conditions Sunday as still "challenging," but two of the fire fronts, heading towards the localities of Jalhay and Monschau, were now "under control," according to Interior Minister Bernard Quintin.
A ballet of tractors hauling water tankers to assist the fire crews was seen near the blaze's edge in Baelen, in addition to a ballet of tractors hauling water tankers to assist the fire crews, while overhead, helicopters carried in water drawn from a nearby lake.
From 80 hectares (200 acres) burned on Friday, the day the fire started for reasons still unknown, the area affected jumped to 850 hectares Saturday morning and by early Sunday had spread to 3,000 hectares.
The blaze broke out in an area that was ravaged by massive fires in 1911, during a similar period of heat waves and drought, and is the country's largest wildfire since then. The entire area has been blanketed by a thick plume of yellowish smoke, prompting the partial evacuation of two villages close by.
Around 20 people spent the night in a local sports hall, the Liege governor's office said, with others believed to have found shelter with friends and family, or in some cases ignored evacuation orders to stay home.
Fumes have traveled as far as neighboring Namur province, where authorities had to ask residents to stop saturating emergency phone lines with reports of the smell.
The governor's office said shifting winds had complicated firefighters' efforts but that "the defensive line protecting evacuated areas is holding." "No homes have been affected at this stage, although the fire remains close and smoke levels are significant," it said.
Firefighters from across Belgium and from Germany have been deployed to assist, supported by next-generation fire engines. But authorities said operations were "particularly complex" because of the fens' terrain, a patchwork of heath, peat bogs and raised wooden boardwalks where heavy vehicles risk sinking into the ground, and firefighters struggle to tackle the fire at close range.
They were counting heavily on aerial assistance to bring the situation under control.
European Commissioner Hadja Lahbib said that two water-bombing aircraft had arrived from Sweden, backing up four helicopters, two Belgian and two Dutch, already on site.
A liaison officer was tasked with coordinating the aerial resources "to prevent accidents," she said.
"Thank you to our European partners for the assistance they are providing," Belgian Prime Minister Bart De Wever wrote on X. Like much of Europe, Belgium has experienced a new spell of intense heat and drought in recent days.
Temperatures reached as high as 37 degrees Celsius (98.6 degrees Fahrenheit) in some parts of the country on Friday, creating conditions conducive to wildfire outbreaks. But rescue teams have been unable to access the area where the High Fens fire first broke out, meaning its precise cause remains unknown.