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 stretched to breaking point by wave of wildfires.
Authorities call on parents to report children if suspected of starting blazes.
Fires  'turned the valleys black' and devastated wildlife in surrounding area.