An oil well blowout in Wyoming prompted 50 residents to evacuate their homes amid concern that a spewing cloud of natural gas could explode.

Gas continued to erupt from the ground Wednesday after the blowout Tuesday afternoon five miles northeast of Douglas in east-central Wyoming. Witnesses told television station KCWY-TV they could hear the roaring gas from six miles away.

Authorities were concerned about the possibility of an explosion or fire before the well could be plugged with drilling mud. No workers were injured.

"I'm hoping this thing doesn't catch on fire because they have a good chance of salvaging the rig and the well bore," said Tom Doll, supervisor of the Wyoming Oil and Gas Conservation Commission, which oversees oil and gas drilling in the state.

The gas leak was diminishing Wednesday and officials were optimistic that workers with the Houston-based well control company Boots & Coots would plug it soon, Doll said.