Dozens of attackers armed with guns, rockets and hand grenades have stormed a cluster of private coalmines in south-western Pakistan on Friday, shooting some miners in their sleep and others after lining them up, killing at least 21, police have said.

The attack by about 40 armed men days before Pakistan hosts a summit of the Shanghai Cooperation Organisation grouping is the worst in weeks in the restive, mineral-rich province of Balochistan bordering Afghanistan and Iran.

“The armed terrorists remained for around one-and-a-half hours in the mining area,” regional police official Asif Shafi said. “They fired rockets and hurled grenades at the mines and miners’ quarters.”

The attackers also set fire to machinery on-site, said a senior government official in the district, Kaleemullah Kakar. Seven more people had been wounded, he said.

There was no immediate claim of responsibility for the attack on the small mines of the Junaid Coal Co in the Duki area. Among the dead were four Afghan nationals, while 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 chair of the district council.

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

A decades-long insurgency in Balochistan – Pakistan’s poorest province – by separatist militant groups has led to frequent attacks against the government, army and Chinese interests in the region to press demands for a share in mineral-rich regional resources. Several attacks have targeted migrant workers, including some from Afghanistan, employed by smaller, privately operated mines.

The attacks have risen in recent months, said the provincial 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. “We condemn it strongly and we will take all-out action against it.

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

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

Besides the separatists, the region is also home to Islamist militants, who have resurged since 2022 after revoking a ceasefire with the government. Two Chinese nationals working for a power plant were killed this week in a blast in the southern city of Karachi, for which the Baloch Liberation Army (BLA) – one of several insurgent groups battling the government – claimed responsibility.

The BLA was also behind Balochistan’s most widespread violence in years in August, which targeted police stations, railway lines and highways, killing more than 70 people. Armed men who stormed the residence of labourers from the eastern province of Punjab last month killed seven.

On Friday, crossfire between police and attackers killed two suspected militants involved in a 2021 attack on dam project workers that killed 13, including nine Chinese nationals.

With Agence France-Presse