The operation has grown to nearly 1,300 firefighters and 335 vehicles from national and volunteer fire services, alongside 120 Territorial Defence Force soldiers and more than 130 police officers.
Two police Black Hawk helicopters are carrying out water drops over the most threatened areas.
Mazovian Governor Mariusz Frankowski, speaking at a Saturday briefing, said the area affected – around 300 hectares – was now "secured and closed", but cautioned that the situation remained dynamic.
Forecast storms could help douse the flames, he said, but strong gusts risked reigniting embers.
Fire commanders said crews were cutting firebreaks along the northern perimeter, which poses the greatest risk of further spread, while continuing to check areas that had appeared to be under control since Thursday.
Around 100 residents remain evacuated from the area.
National road 50 stays closed until operations conclude.
Police said they were still looking into reports the fire may have been started deliberately.
(ał)
Source: PAP