Francis National Forests in Oklahoma and Arkansas have prescribed burns planned over the next several months are necessary to promote natural ecological processes “The first objective of prescribed burns is to reduce the potential for large costly catastrophic wildfires,” said Joshua Graham Francis National Forests Fire and Aviation Staff Officer Prescribed burns tend to take place in either the winter or the growing season which starts in the middle of March dormant season burns are very effective at reducing threats to forest health “Other important objectives include improving habitat for a wide variety of wildlife endangered Indiana Bats or Red Cockaded Woodpeckers and others which are all essential in the balance of natural processes.” Several conditions must be met before a prescribed fire including the combination of the correct humidity Francis National Forests said it will notify the public on days when prescribed fires are scheduled in their area The USDA Forest Service is also reminding the public to keep drones away from fire activity Flying drones or unmanned aircraft systems near a prescribed fire or wildfire is illegal and can seriously hinder firefighters' ability to manage the burn and local laws may subject the offender to civil penalties BERLIN (AP) — Firefighters struggled Friday to tame a wildfire southwest of Berlin but had to maneuver carefully as the blaze set off old World War II ammunition that is still buried in the forests around the German capital Flames forced the evacuation of several nearby villages and sent clouds of acrid smoke toward the German capital The fire, which was the size of 500 soccer fields, has already set off several detonations of old ammunition according to local lawmaker Christian Stein Firefighters were not allowed to enter suspicious areas The fire started Thursday afternoon and spread quickly through the dry pine forests in the Treuenbrietzen region 30 miles outside of Berlin in the eastern state of Brandenburg authorities had evacuated 500 people from the villages of Frohnsdorf 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 Overnight, winds blew the smoke to Berlin where people in some neighborhoods were told to keep their windows closed In some cases the smell of smoke was so strong that residents called Berlin emergency services More than 600 firefighters and soldiers were brought in to battle the wildfire Several roads were closed and local trains halted service in the area close to the fire Stein said the fact that the fire broke out in several places simultaneously suggested it could have been arson but Brandenburg's Interior Ministry said it was still investigating the cause of the fire and large parts of the country are on high alert regarding possible wildfires who is in charge of forests in the state of Brandenburg said 400 wildfires have already been reported this year Firefighters battling blaze in Brandenburg are hampered by unexploded war munitions Berlin residents have been told to shut windows and doors after a large forest fire sent a giant plume of smoke across the city, with unexploded munitions from the second world war complicating firefighting efforts. The blaze, which began on Thursday afternoon, spread quickly overnight to engulf 400 hectares (1,000 acres) of forest between the Brandenburg town of Treuenbrietzen and village of Jüterborg, 39 miles (63km) south-west of the German capital. Read moreFlames lit up the forest as fire crews deployed water cannon and joined helicopters army and police officers in an attempt to control the inferno Fire crews had stopped its spread on Friday night but he warned the danger from the blaze had not yet passed “The situation has not yet calmed down,” a spokesman for the interior ministry of Brandenburg state told the DPA news agency A fire brigade spokesman told the newspaper Bild: “We can’t get to a lot of places only the paths that have been cleared and are accessible.” A firefighter Firemen work in Treuenbrietzen near Berlin Photograph: Michael Kappeler/AFP/Getty ImagesLarge swathes of the forest are considered too dangerous to access on foot given the danger of unexploded hand grenades and shells some of which have already been set off by the fire More than 500 residents were evacuated to emergency shelters on Thursday as the flames threatened to engulf three villages Residents were told to bring only vital medicines and important documents Emergency services cleared tracks into the forest overnight using wheel loaders They succeeded in stopping the fire within hundreds of metres of residential buildings A firefighter helps to put out a forest fire near Treuenbrietzen. Photograph: Hannibal Hanschke/ReutersA plume of smoke visible six miles away disturbed Berlin residents when it drifted over the city in the early hours of Friday. Many reported waking up to the smell of burning. Berlin fire services told Bild that whole streets were blanketed in smoke and instructed residents to shut windows and doors and turn off air conditioning units. The “whole city area” was affected by smoke, Berlin fire service said early on Friday, adding that due to the smell of burning it was responding to “a great many emergency calls and reports of fires”. Flights to and from Berlin’s airports were unaffected by the smoke, but one regional railway line and a road were closed. By mid-morning, fire services reported that they had got the situation largely under control. However, the Brandenburg interior minister, Karl-Heinz Schröter, told Bild it would likely take another few days to entirely quell the flames. Notifications can be managed in browser preferences. More than 500 people forced to leave their homes as a result of the blaze I would like to be emailed about offers, events and updates from The Independent. Read our Privacy notice People from three villages have been forced to leave as the blaze which is now the size of 500 football pitches because one cannot step on the ground and therefore one cannot get close to the fire" to extinguish it More than 500 people had to leave their homes as a result of the fire in the Treuenbrietzen region some 50 kilometres (30 miles) outside of Berlin "The fire continues to be a big threat," Mr Woidke said "But we will do everything to protect people's property." Local lawmaker Christian Stein said there had already been several detonations due to the ammunition and that firefighters were not allowed to enter some areas the authorities were trying to douse the flames in those areas with firefighting helicopters and water cannons The fire started on Thursday afternoon and spread quickly through the dry pine forests the authorities had evacuated the villages of Frohnsdorf where people in some neighbourhoods were asked to keep their windows closed Berlin emergency services received calls from concerned Berliners who were woken by the strong smell of smoke More than 600 firefighters and soldiers have been brought in to battle the wildfire They are trying to cut trees to make long swaths in the forests to prevent the fire from spreading further Several roads were closed and local train operators stopped their service in the area close to the fire Germany has seen a long, hot summer with almost no rain, and large parts of the country are on high alert regarding possible wildfires. 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