KHAR, Pakistan – Pakistani troops killed eight Islamist militants Tuesday in an Afghan border region where insurgents are staging a comeback after a military operation there was declared a success, a local official said. The fighting came amid continuing reports that the head of the Pakistani Taliban had died as a result of injuries sustained in a US missile strike elsewhere in the northwest in mid-January. On Monday, a Taliban commander said chief Hakimullah Mehsud was alive and promised to provide proof soon. The clashes in the Bajur region illustrate the tenacity of Islamist militants in northwest Pakistan, most of whom are allied with those waging war against US and NATO troops across the border in Afghanistan. Bajur was declared free of militants a year ago after a military offensive, but in recent days government officials say security forces have killed dozens of insurgents there. A militant suicide attack there killed 16 people on Saturday. The latest deaths came during overnight raids in the towns of Damadola and Sewai, local government official Abdul Malik said. He said tribesmen loyal to the government hung the corpses of two alleged militants from an electricity pole in the Inayat Kali area in Bajur, though he did not know when the insurgents were killed.