According to sources, the blast took place in a coalmine in the Doli area of Lower Tehsil. Subsequently, two people were killed on the spot whereas four others sustained injuries.
The wounded persons were shifted to District Headquarters Hospital where their condition was reported as critical.
There are more than 4,000 coalmines in Orakzai tribal agency. Over 3,000 labourers work in these mines. Most of the coalmines in Orakzai are notorious for poor safety standards and facilities, according to local sources.