At least 10 Pakistani soldiers were killed in an attack on a security check post near the country's southwestern border with Iran, the Pakistan Army said.
In a statement issued on Thursday, the army said "terrorists" carried out the attack in the Kech area of Balochistan province.
"1 terrorist was killed and several injured," the army added.
Later in a search operation, three terrorists were arrested.
The Balochistan Liberation Front, an outlawed militant group in the province, claimed responsibility for the attack.
Prime Minister Imran Khan strongly condemned the attack.
The large Balochistan province is strategically important due to the rich resources of copper, zinc and natural gas.
Balochistan, which makes up 42% of Pakistan, is a key route to the $64 billion China-Pakistan Economic Corridor, which aims to connect China's strategically important northwestern Xinxiang province to the Pakistani port of Gwadar through a network of roads, railways and pipelines to transport cargo, oil, and gas.