Islamabad, Mar 20 (IANS): Twelve labourers were killed and eight others injured in an explosion in a coal mine in Pakistan's Balochistan province, officials said on Wednesday.

The explosion occurred on Tuesday night as toxic gas accumulated inside the cave in Harnai district of the province, Abdul Ghani Baloch, chief inspector of mines of Balochistan, told Xinhua.

He said that 12 labourers were working inside the mine when the blast happened and eight more laborers entered the mine trying to rescue their trapped colleagues, Xinhua news agency reported.

"Unfortunately, further collapsing of the coal mine trapped them as well," he added.

The rescue teams have completed the operation and recovered 12 bodies and eight injured from the mine, he added.

The injured people have been shifted to a nearby hospital.

In a statement, Pakistani Prime Minister Shehbaz Sharif expressed deep sorrow and grief over the loss of precious lives in the incident.