A war on gophers waged by two Canadian men went awry this weekend when a device used to blast the rodents in their holes sparked a massive grass fire in a rural area near Calgary, Alberta, causing more than C$200,000 ($197,000) in damages.

Despite a ban on fires in the tinder-dry area of Springbank, just northeast of Calgary's city limits, two men went into a field to kill gophers using a device called a Rodenator, fire officials said on Monday.

The device pumps a mixture of propane and oxygen into gopher holes, which is then ignited, and, according to the manufacturer's Web site, the resulting blast creates a shock wave that kills the gopher and collapses its tunnel system.

"We had a couple of acreage owners out taking care of their rodent problem with this device," said Captain Joe Garssi of the municipal district of Rocky View's fire department.

"They did a few holes successfully and then hit a hole that didn't go in very far. When they filled it with propane it over-filled the hole...and when they ignited it (fire) flashed
out of the hole into the grass beside them."