Two people were killed and three others critically injured after a fire erupted at an oil drilling rig in southeastern Oklahoma early Friday morning, officials said, adding that investigators from the federal Occupational Safety and Health Administration, or OSHA, were headed to the scene.

The oilfield workers, identified as 26-year-old Gary Keenen of Ada and 27-year-old Kelsey Bellah of Tulsa, died after suffering injuries during an explosion at the rig about 2 miles west of Coalgate in a remote area of rural Coal County about 100 miles southeast of Oklahoma City, CBS affiliate KWTV in Oklahoma City reported.

"We had a fire at an oil derrick and there were two individuals that were killed," Sam Schafnitt, chief of operations for Oklahoma's Office of the State Fire Marshal, said by telephone.

Out of the three injured workers, two were transported to trauma centers in critical condition, while another sustained burns to his hands, he said.

The accident at the rig, which is owned by Pablo Energy of Amarillo, Texas, occurred off Highway 31, near the town of Coalgate, which is about halfway between Dallas and Tulsa, Okla., the Associated Press reported.

"This happened in a very rural area of the state, so we still don't have many details," Schafnitt said.

However, there were no reports that the explosion and fire had caused any environmental damage that would require subsequent cleanup or precautionary evacuations, Matt Skinner, a spokesman for the Oklahoma Corporation Commission that regulates the oil and gas industry, said, adding that he wasn't aware if the fire was still burning.

Meanwhile, Coal County Sheriff Bryan Jump, who is at the scene, was not immediately available for comment. A telephone call to Pablo Energy was also not immediately returned.

The accident in Oklahoma comes one month after a worker for Halliburton Co. was killed in Colorado while conducting hydraulic fracturing operations, according to Nasdaq.