Pakistan’s army has launched an offensive against the Taliban guerrillas in its mountainous tribal border region, the army’s chief spokesman said Monday. Troops have moved into Kurram Agency, which the Taliban has used as a base in Pakistan. While Major General Athar Abbas confirmed the attack, he did not give any details. Pakistani media reported that residents and officials said thousands of troops were involved. Taking control of the Kurram Agency could help block the Taliban’s access to North Waziristan, Pakistan’s biggest remaining guerrilla stronghold and where the U.S. has ordered Pakistan to conduct a ground offensive. As the army offensive began in Kurram, more than 1,000 families fled the region to escape the fighting.