Gunmen have killed at least 20 workers at a construction site in a remote part of the Baluchistan Province's Turbat district, the New York Times reports. Officials believe that the attack was carried out by a separatist group that's operated in the region for decades.

According to the Times, the attack came between 2 a.m. and 3 a.m. "The laborers were working on a bridge that links Turbat to a national highway," Turbat's top police official Imran Qureshi said. "They opened fire on the laborers, most of whom were sleeping." No one has yet claimed responsibility for the attack.

Government commissioner Pasand Khan Buledi told the Associated Press that 16 of the dead were from Pakistan's Punjab province and four from Sindh province. He also said that the eight guards—all of whom are from Baluchistan—were unharmed.

This follows the pattern of previous separatist attacks, the AP reports, in which gunmen have killed people from Pakistan's most populous province, Punjab, and those from Baluchistan are freed.

The construction site is in what Qureshi referred to as the "B-Area," which the Times describes as "tribal regions of the province where the police do not exercise authority." Security there is provided by a paramilitary force, the Baluchistan Levies. Baluchistan is Pakistan's largest province by area and abounds with mineral resources and natural gas.

Photo credit: Getty Images. Contact the author of this post: brendan.oconnor@gawker.com.