Gunmen in southwestern Pakistan have killed at least 11 workers at a remote coal mine, officials said Sunday.

The victims of the attack in Baluchistan province were from the minority Shiite Hazara community.

"Dead bodies of the 11 miners have been taken to a local hospital," Khalid Durrani, a government official in the area, told AFP.

Ethnic Hazara make up most of the Shiite population in Quetta, the capital of Baluchistan -- the country's largest and poorest region, rife with ethnic, sectarian and separatist insurgencies.

They are often targeted by Sunni militants, who consider them heretics, though it was unclear why the attackers targeted the coal mine specifically.

The attack, before dawn on Sunday, took place in the far-flung and mountainous Machh area -- 60 kilometres southeast of Quetta -- while the miners slept, Durrani said.

A security official told AFP the attackers first separated the miners, tied their hands and feet, took them out into the hills and later killed them.

Both Durrani and the security official said the victims belonged to the Hazara community.

Durrani said the mine was deep in the mountains.

Abid Salim, a top government official in the area, told AFP "they tied their hands and feet and brutally slaughtered them with some sharp instrument".

Some of the victims were beheaded, he added.

The assailants fled after the attack. Both officials said police and members of the local paramilitary force were on the scene, where a search operation had been launched to trace the attackers.

Dozens of local people and family members briefly blocked a main road in the area, demanding protection.

No group has yet claimed responsibility for the attack.

In a tweet, Prime Minister Imran Khan condemned "the killing of 11 innocent coal miners in Machh" as a "cowardly inhumane act of terrorism".

Liaqat Shahwani, a spokesman for the provincial government, confirmed the incident and told private TV channel Geo that it was an act of terrorism.

Though Pakistan's mines are notorious for poor safety standards, such attacks against miners are rare.

Pakistan