Four miners suffocated to death due to the accumulation of carbon monoxide in a coal mine in the Kala Khel area of Khyber Pakhtunkhwa's Khyber district, a statement from the district commissioner's office said on Wednesday.

The bodies were recovered by locals. The statement from the DC office said that the bodies of the victims — all of whom belonged to the Shangla district — have been sent to their hometowns for burial.

According to Khyber district Assistant Commissioner Kashif Qayyum Khan, five miners had entered the coal mine this morning in order to check carbon monoxide levels and suffocated due to a high concentration of the poisonous gas. One of the miners, who was rescued in time, survived while the remaining four were killed.

An inquiry will be carried out to determine if the incident occurred due to the negligence of the mine's leaseholder or the failure of the workers to follow the standard operating procedures, Qayyum said.

Coal mining has historically been fraught with hazards, which are similar to those associated with the aftermath of natural disasters: suffocation, gas poisoning, roof collapse, rock burst, gas explosions and a plethora of lung diseases, including incurable diseases like coalworker's pneumoconiosis, also known as black lung disease.

These risks can be substantially mitigated with the adoption of the requisite safety measures.