Gunmen kill seven bus passengers in southwest Pakistan

Unknown gunmen shot dead seven passengers on a Lahore-bound bus in southwestern Pakistan's Balochistan provinceafter forcing them off the vehicle and checking their identity documents late on Tuesday, officials said.

Balochistan, bordering Afghanistan and Iran, is a key battleground in Pakistan's fight against separatist insurgents, who want greater autonomy and a share of the region's natural resources.

In recent months, there has been a surge in attacks on security forces, Chinese infrastructure projects and workers from richer central Punjab province, who the militants see as exploiting Baloch resources.

The group of around 40 men stopped multiple buses and vehicles along a highway in Balochistan's Barkhan district, checking national identity cards before pulling seven passengers off the bus and shooting them, senior government official Waqar Khurshid Alam told Reuters.

All seven victims were from Punjab, Alam said.

"Armed men dragged my elder brother from the bus after checking his identity card, but they did nothing with us," a woman from the city of Faisalabad in Punjab said in a video seen by Reuters.

No group has claimed responsibility for the attack, and the motive behind the killings was unclear. Officials told Reuters that the area had been cordoned off but the attackers had escaped.

Pakistan's Prime Minister Shehbaz Sharif said the gunmen would be brought to justice.

"Those who harm the lives and property of innocent citizens will have to pay a heavy price," Sharif said in a statement.