Consol was using 10 mine rescue teams to battle the fire, Associated Press reported. Carbon monoxide levels were being monitored from the surface to detect if the fire was going out.
Mine officials were unsure how the fire started but said it was burning in an area about 183m underground in a restricted area where grids of tunnels used to move miners and machinery intersect.
"Because of all these underground detectors we were able to get organised before the fire spread very far," Consol spokesperson Tom Hoffman told the news service.
A fire in another Consol mine, Loveridge, burned for weeks in 1999 and led to the closure of the mine for two years. About 200 miners laid off due to the fire were recalled last week.
