OSHA probing Kansas oil-drilling blast that injured 5

Federal workplace safety officials are investigating a western Kansas oil field explosion that injured five workers, two of them critically.

The U.S. Department of Labor's Occupational Safety and Health Administration says the accident Monday near Sharon Springs in Wallace County happened while workers were performing a drill stem test.

The medical conditions of the victims, who according to OSHA were affiliated with Wichita-based Murfin Drilling Co., were not immediately available Tuesday.

Phone messages that The Associated Press left with Murfin were not immediately returned.

Fire Chief Jay Sharp says crews were working when gas made its way onto the deck floor of a warming hut, which included running heaters.

Sharp says responding crews were able to put the fire out quickly.