QUETTA: Dozens of attackers armed with guns, rockets and hand grenades stormed a cluster of small private coal mines in Duki area on Friday, slaying some miners in their sleep and shooting others after lining them up, killing at least 21 in the restive region, police said.

The attack by around 40 armed men days before govt hosts a summit of the Shanghai Co-operation Organization grouping is the worst in weeks in the Balochistan bordering Afghanistan and Iran.

“The armed terrorists remained for around 1-1/2 hours in the mining area,” regional police official Asif Shafi told Reuters. “They fired rockets and hurled grenades at the mines and miners’ quarters.”

There was no immediate claim of responsibility for the attack on the mines of the Junaid Coal Co in the Duki area, which also injured six.

Among the dead were four Afghan nationals; another four were injured.

Afghanistan’s Ministry of Foreign Affairs strongly condemned the attack in a statement, and assigned its Quetta consulate to facilitate the transfer of the bodies.

Businesses and shops were shut in Duki as hundreds of people gathered along with the bodies of the dead in a protest to demand the arrest of the attackers, police said.

“We were receiving threats from the militants for some time but there was no information about the attack,” said mine owner Khairullah Nasar, who is also the chairman of the district council.

The attackers burnt down all 10 mines, along with the equipment and machinery within, he added.

The attacks have risen in recent months, said Governor Jafar Khan Mandokhel, who called the miners’ killing an inhuman act.

“On one side you talked about your independence and your rights and on the other hand you are killing innocent labourers,” he told a news conference, referring to the separatist militant groups, adding, “We condemn it strongly and we will take all-out action against it.”

The government was “determined to root out all forms of terrorism”, Prime Minister Shehbaz Sharif said in a statement.

“The provincial government has ordered an investigation and a case has been registered against unknown assailants under the terrorism law,” a government official said, speaking on condition of anonymity.