The death toll has risen to 23 due to collapse of two coalmines in two separate incidents near Quetta, reported Radio Pakistan.
Twelve coal miners have also been injured in both the incidents.
"The roof caved in following an explosion triggered by the accumulation of methane gas, killing 23 miners and wounding two others", Jawaid Shahwani, commissioner of Quetta Division said.
Shahwani said 25 workers were inside the mine when the explosion occurred, adding that all the injured miners had been rescued and taken to the hospital.
"We are trying our best to recover bodies but it will take time as most of the bodies are buried very deep", he said.
Deputy Commissioner Quetta, Dr Farukh Atique said the injured have been shifted to civil hospital where they are stated to be out of danger.
At least 43 workers were killed in March 2011 when explosions triggered a collapse in a coal mine in Balochistan.
A total of 25 person were trapped after a gas explosion in Pir Ismail, Marwar (45 km from Quetta) at around noon. Their bodies were later recovered after hours-long rescue operation.
The Quetta deputy commissioner, Provincial Disaster Management Authority (PDMA) rescue team, local labourers, the inspector mines, Frontier Corps (FC) personnel and District Administration Levies force QRF were also present at the site.
PHOTO: EXPRESS
Two killed, five still trapped at PMDC mine in Quetta
Meanwhile, rescue sources say nine more workers were reportedly trapped in another mine due to gas inhalation at the Pakistan Mineral Development Corporation (PMDC) mine in Quetta.
Two bodies have been recovered and as many injured labourers evacuated, they said, adding that at least five more miners were still trapped in the mine.
Rescue efforts were underway.
Earlier this week, six labourers working on network installation for a private telecommunication company were shot dead by unidentified men in Kharan district.
According to levies forces, the labourers, who hailed from Punjab, were working without any security and did not have a no objection certificate (NOC). The Frontier Corps (FC), levies forces and administration reached the site of the incident and shifted the bodies to Civil Hospital.