QUETTA, Pakistan (AP) — Gunmen killed 20 miners and wounded another seven in Pakistan’s southwest, a police official said Friday.

It’s the latest attack in restive Balochistan province and comes days ahead of a major security summit being hosted in the capital.

Police official Hamayun Khan Nasir said the gunmen stormed the accommodations at the coal mine in Duki district late Thursday night, rounded up the men and opened fire.

Most of the men were from Pashtun-speaking areas of Balochistan. Three of the dead and four of the wounded were Afghan.

Nobody claimed immediate responsibility for the attack.