ISLAMABAD — Pakistan's military said it killed two militants on Sunday in a shootout in the country's northwest, a former militant stronghold.

A third militant was arrested following the operation in the town of Mir Ali in North Waziristan district. The army statement said the militants had been involved in several attacks on civilians and security forces.

This was the second such operation in North Waziristan in recent days. Two militants were killed by the army some 6 kilometers (4 miles) north of Mir Ali on Friday

The mountainous areas of Khyber Pakhtunkhwa province along Pakistan's border with Afghanistan served as a base for the Pakistani Taliban and other militants until a few years ago, when the army said it cleared the region of insurgents. Occasional attacks have continued.

Such attacks have raised fears that the Pakistani Taliban are regrouping. Last month, the insurgents released a statement asking residents to vacate the province's former tribal regions, as the group plans to launch more attacks on security forces.

In September, two Pakistani soldiers were killed in a shootout with militants during a search operation in North Waziristan. Earlier that same month, the Pakistani Taliban took responsibility for a powerful roadside bombing in the same district that targeted a military vehicle, killing three soldiers and wounding four.

The Pakistani Taliban, also known as Tehreek-e-Taliban Pakistan, are a separate insurgent group from the Afghan Taliban, although Pakistan's militant groups are often interlinked with those across the border in Afghanistan.