People wait at the entrance of a coal mine for news of their loved ones after an explosion in Pakistan [REUTERS]

At least six miners have been killed and 45 others trapped underground after explosions triggered a collapse in a coal mine in Pakistan's Baluchistan province, officials say.

The miners were working around 1,200 metres underground in the mine at the time of the blasts on Sunday. Officials said that hopes for the survival of the missing were slim.

The mine in the Sorange district of the war-torn province was poorly ventilated and gas accumulated, followed by three blasts, they said.

"We have retrieved three dead bodies and are trying to rescue 45 other miners trapped inside but there are less chances of their survival" Mohammad Iftikhar, a provincial chief inspector of mines, told the AFP news agency.

"Miners died of suffocation, still a huge quantity of gas is causing difficulties in rescue work."

Akbar Hussain Durrani, Baluchistan's home secretary, confirmed the incident.

The coal mine is run by the state-owned Pakistan Mineral Development Corporation.

Rich in mineral wealth, Baluchistan is plagued by an uprising blamed on nationalist tribesmen demanding more jobs and royalties from the region's natural resources. Hundreds of people have died in the violence since 2004.

Most coal mines in the impoverished province are notorious for poor safety standards and facilities. Similar deadly accidents have occurred in the past.