German authorities say they’re making progress fighting a major forest fire some 50 kilometers (30 miles) outside Berlin, but an area around two evacuated villages remains a source of concern.

The blaze near the town of Treuenbrietzen started Thursday afternoon and spread quickly through bone-dry pine forests. It has at times sent smoke toward the German capital.

A senior local official in Potsdam-Mittelmark county, Christian Stein, said Saturday that “we managed during the night to get a grip on the fire,” with some large areas extinguished. But he said that, around the villages of Klausdorf and Tiefenbrunnen, the blaze is still flaring up.

Inhabitants were allowed Friday to return to a third village, Frohnsdorf.

Firefighters have to maneuver carefully because old World War II ammunition is still buried in the region.

The fire, which was the size of 500 soccer fields, set off several detonations of old ammunition. Firefighters were not allowed to enter suspicious areas.

“The ammunition is very dangerous, because one cannot step on the ground, and therefore one cannot get close to the fire” to extinguish it, Brandenburg state’s governor, Dietmar Woidke, told reporters.

“Something like that, we didn’t even experience during the war,” 76-year-old Anita Biedermann told the dpa news agency as police told her to grab her jacket, ID and medication from her home before taking her to a nearby gym for the night.

Firefighters were trying to douse the flames in areas they could not enter with water-bearing helicopters and water cannons.

(AP)