PESHAWAR, Pakistan — Militants staged a pair of attacks against anti-Taliban figures in northwestern Pakistan on Sunday, killing one of the men as part of an escalating campaign to weaken the country’s resolve to fight Islamic extremism.

Militants have killed more than 300 civilians and security force personnel in the last month in retaliation for an army offensive launched in the tribal area of South Waziristan, where al-Qaida and Taliban leaders are believed to be hiding.