ISLAMABAD — The Taliban have fled the Pakistani army’s advance on the main town in the Swat Valley, delivering the military a strategic prize in its offensive against militants in the country’s northwest, commanders said.

Fighters had dug themselves into bunkers built into hotels and government buildings in Mingora, and initially offered stiff resistance as troops first closed roads leading to the town then began moving in earlier this week, army spokesman Maj. Gen. Athar Abbas said.

Aid was being distributed Saturday to some of the estimated 20,000 people who were trapped in Mingora. Abbas said 1,217 militants have been killed in the Swat offensive and 79 arrested, and 81 soldiers have died. The military has not released civilian casualty numbers and says all care is being taken to protect the innocent.