At least three labourers were killed and one was injured in a blast inside a coal mine in Darra Adam Khel, Radio Pakistan reported Saturday.
All the labourers belonged to Shangla district.
The injured was shifted to Peshawar’s Lady Reading Hospital, the police said.
On September 12, nine labourers were killed in a similar explosion in a coal mine in Kohat district.
Poor working conditions inside coal mines in the country have claimed hundreds of lives.
According to the Pakistan Central Mines Labour Federation, 100 to 200 labourers die on average in coal mine accidents every year.