It will take two years to clear the tens of thousands of trees smashed by the weekend storms that devastated Poland's forests, the country's forest service said Wednesday.

"We're dealing with what is undoubtedly the worst disaster in the history of Polish -- and perhaps even European -- forestry," Poland's chief forester, Konrad Tomaszewski, told reporters.

The storms that hit Poland overnight Friday to Saturday killed six people, including two Girl Guides crushed by a falling tree while camping in a forest.

Aerial television footage in vast swathes of forest where trees had been snapped like matchsticks.

According to Tomaszewski, the storms brought down an estimated 8.2 million cubic metres of lumber.

It would take two years to clear the debris and begin replanting trees and decades to recover the lost natural habitats of birds and other wildlife, he added.

More storms are forecast for the coming weekend.

The storms also caused serious damage to thousands of households, ripping off roofs and downing power lines, mostly in northern and western regions of Poland.

Critics have accused the country's rightwing populist Law and Justice (PiS) government of being slow to send in help to areas that suffered the most damage.

The disaster comes as Poland is under fire for ignoring a ban imposed by the EU's top court on logging in the Bialowieza forest, Europe's last primeval woodland.

The European Court of Justice on July 27 ordered Poland to suspend logging in the forest pending a final judgement.

The EU had taken Poland to court arguing that the operations were destroying a UNESCO-listed forest that boasts unique plant and animal life.

According to Poland's forest service, loggers harvested some 111,993 cubic metres of wood in Bialowieza between January and August.