The passengers had been kidnapped from multiple buses on Thursday evening, said the provincial government spokesman Shahid Rind.

Their bodies with bullet wounds were found in mountains overnight, another government official Naveed Alam said.

No one has claimed responsibility.

Separatist Baloch militants have in the past been involved in such incidents, killing passengers after identifying them as coming from the eastern Punjab province.

The Baloch Liberation Army is the strongest of a number of insurgent groups long operating in the area bordering Afghanistan and Iran, a mineral-rich region.

The ethnic Baloch militants blame authorities in Pakistan for stealing their regional resources to fund spending in Punjab province.