By Keith Coffman
DENVER, Aug 5 (Reuters) - The U.S. Forest Service banned the use of exploding shooting targets on drought-parched national forests and grasslands in five states on Monday, after authorities blamed the devices for sparking 16 wildfires since last year.
The so-called "binary exploding targets," popular among firearms enthusiasts who use them for target practice, are made of canisters containing two chemicals that blend and explode when struck by a bullet.
The targets have become too risky to allow on tinder-dry national lands in the Rocky Mountains region that have been in the grips of a multi-year drought, authorities said.
"When detonated, the exploding targets often result in a fireball that can ignite vegetation and surrounding materials," according to a joint statement by the forest service and the U.S. Attorney's Office in Denver.
The current fire season has been particularly deadly in the U.S. West, with at least 22 fatalities reported since June, among them two people caught in a Colorado fire and 19 firefighters in Arizona. None of the fatal fires were caused by exploding targets.
The crackdown on the targets covers the 17 national forests and seven grasslands the forest service manages in its Rocky Mountain region which includes Colorado, Wyoming, Kansas, Nebraska and South Dakota.
The U.S. Forest Service has blamed the targets for lighting 16 wildfires since 2012, seven of them in the five-state region under the ban. The blazes together cost more than $33 million to put out.
In conjunction with its regional offices, the forest service is "developing a national approach" to deal with the issue, spokesman Larry Chambers said in an email.
Even unexploded targets pose a hazard to wildland workers and visitors, said Laura Mark, the U.S. Forest Service's regional special agent in charge.
"Explosives ordnance demolition experts have had to respond on three occasions this year to safely dispose of unused targets that had been mixed but not yet used," Mark said.
The U.S. Bureau of Land Management is also exploring banning the targets on the 8.1 million acres (3.3 million hectares) of public land it manages in Colorado, according to BLM Ranger John Bierk.
Violators of the newly imposed ban face fines up to $5,000 and a maximum six months in prison. (Editing by Tim Gaynor and Mohammad Zargham)