United Kingdom — Resources are being stretched as the numbers of grass fires in south Wales reached 200 in a week, according to the Fire Brigades Union (FBU).
It has concerns too that the fires could result in a member of the public or a fire fighter being injured.
The FBU said there had been more than 1,100 calls in a week, particularly in the heads of the valleys area.
On Thursday night, 150 calls were received within a few hours, with the biggest over Merthyr Tydfil.
It affected about 500 hectares (1,200 acres) on a mountain behind the Asda supermarket site and could be seen across the skyline after dark.
South Wales Fire and Rescue crews also had calls to Ebbw Vale and Tredegar.
Mark Watt, FBU secretary for south Wales, said he was concerned about “public and fire fighter safety”.
In the last three years 18 fire fighters have been injured on call, which has resulted in nearly 280 days lost on duty.
He said that although no-one had been seriously injured yet, “I think it’s only a matter of time before something more serious occurs.”
“From 6 o’clock on Friday 26 April to 6 o’clock on Friday 3 May the fire service in south Wales received 1,130 calls to grass fires which resulted in nearly 200 incidents,” he told the BBC Radio Wales.
“It puts a lot of strain on resources and obviously we deal with any incident as they come in as best we can.
“But when you’re taking the local appliances away for long periods of time to deal with grass fires obviously it delays the attendance of an appliance at any more serious incidents.”
Mr Watt said it was “massively disappointing” that most of the fires were started deliberately.
He added there had been a few arrests but those cases had not gone through the court process yet.
“Traditionally, the grass fire season is over the spring period in particular the school Easter holidays and South Wales Fire Service has put into place many projects to try to reduce this.
“It’s a perennial problem that’s achieving nothing except a drain on resources,” he added.