A boy of 11 is among children arrested over a spate of fires across Welsh countryside which have cost £500,000 to fight . Five children were questioned by police after 623 fires ravaged 600 acres of fields and woodland this month alone . Fire crews in South Wales say they have been stretched to breaking point by the ‘ unprecedented ’ scale of destruction , which is mainly being blamed on gangs of youngsters . Five children have been questioned after 623 fires ravaged 600 acres of fields and woodland in one month . Officers yesterday called on parents to report their children if they suspect them of lighting fires . Deputy Chief Constable Matt Jukes , of South Wales Police , said : ‘ It is only a matter of time before somebody gets seriously injured or even killed . ‘ What is most concerning is that we believe that many of these grass fires are being caused by children . This must be addressed and everybody can do their bit. ’ ‘ Teachers , neighbours , shop owners , but most importantly parents or carers have a role to play and can make a stand against this recurring problem. ’ DCC Jukes added : ‘ The sad reality is that because of the naïve and reckless actions of some of the youngest members of the community , the lives of those who need the emergency services most are being put at serious risk. ’ From Friday morning to Monday evening , emergency services took more than 1,600 calls for grass fires . Gordon Shumack , of Crimestoppers Wales , said : ‘ The valleys are turning black again as a result of these fires being deliberately started. ’ The cost of fighting the blazes , which devastated wildlife , has risen close to £500,000 since the month began . Fire chief Stephen Rossiter said : ‘ The natural terrain of mountains is very dangerous underfoot , and more so when we are fighting grass fires – even for our best-trained people. ’ South Wales : Gordon Shumack said the valleys were turning black as a result of the deliberately started fires . ‘ It is quite possible a house will catch fire if the incidents continue . People lighting them need to understand the danger they can cause. ’ The arrested 11-year-old was given ‘ stern ’ advice by police . Four suspects aged 12 to 14 were released on bail . It comes as the dry and sunny weather has left heathlands especially vulnerable to fast spreading fire . Meanwhile a blaze which ravaged the Pirbright Army ranges in Surrey was yesterday still smouldering nearly a week after it began . Conservation experts say that the area could take ten years to recover . A man , 33 , has been arrested and released on bail over the fire .
Fire crews in South Wales responded to breaking ground by wave of wildfires . firefighters call on firefighters to protect children if suspected of starting blazes . Fires ' turned the valleys black ' and devastated wildlife in surrounding areas .