Rescue teams from neighbouring Illinois and Pennsylvania are on standby at the mine but are unable to enter until gas and damage levels are assessed.

Local media reported nobody had communicated with the trapped miners since the accident.

The explosion occurred just before 7.30am as miners entered the mine on their first shift after the mine was idled over the holiday period.

Two shuttle cars carrying the miners entered the portal but the second car turned back after hearing or feeling an explosion, Associated Press reported.

The first car never made it out. Four co-workers re-entered the mine shortly after the explosion but were not able to penetrate the mine after coming across a wall of debris, blocking access to the trapped miners.

The Mine Safety and Health Administration have dispatched its Mine Emergency Operations group’s command vehicle with its seismic and gas analysis equipment, as well as the agency’s mine rescue robot, to the mine.

“All available MSHA mine rescue personnel and mine safety specialists are either at the minesite or en route to assist in the rescue,” MSHA acting assistant secretary David Dye said early Monday morning.

“MSHA is using its mine emergency operations group and equipment to lead this rescue attempt and, along with mine company officials, looks to develop a safe plan for rescue of the miners as quickly as humanly possible.”

The Sago Mine, Upshur County, is operated by Anker West Virginia Mining Co and was bought by International Coal in April last year. The bord and pillar mine produced almost 370,000 tonnes of coal last year with 134 miners.

Many people have drawn comparisons of Monday’s accident with the Quecreek rescue in 2002.

The Pennsylvania Quecreek Mine was the focus of world attention from July 24-28 2002, when miners cut through into an abandoned, water-filled mine flooded with over 50 million gallons of water.

Nine miners scrambled to safety, but nine were trapped in a pocket of air in the mine. They were rescued as a result of the combined efforts of state and federal mine rescue agencies and hundreds of volunteers and workers.