Seven Pakistani soldiers were killed late on Saturday in an attack in the southwestern province of Balochistan, the military said on Sunday.
Security sources told Reuters the attack occurred in the district of Harnai. Militants from nearby hilltops opened fire on a military checkpost using rockets and then automatic gunfire.
"[The area] has been cordoned off; escape routes have been blocked," the military said in a statement.
The resource-rich province of Balochistan is home to some of Pakistan's largest coal and natural gas reserves, including some being backed by China.
But Balochistan has largely remained undeveloped, and several armed groups have waged a decades-old insurgency in the region that has targeted the military as well as coal and gas projects backed by foreign investors.
Islamabad has said the insurgency is backed by rival India, and is part of an attempt to thwart foreign investment in the country. "Our nation stands with our courageous soldiers who face attacks from Indian-backed terrorists," Prime Minister Imran Khan wrote on Twitter after the attack.
Ten militants and one soldier were killed on Dec 20 in the Awaran district of Balochistan, according to the military, which described the clash as part of an "intelligence-based" raid on an insurgent location.
In October, seven soldiers and seven security guards were killed by insurgents in the coastal Ormara district of Balochistan as they escorted a convoy of oil and gas workers. That attack was claimed by an umbrella organisation of Baloch militant groups.