Kifayatullah, Mohammad's eldest son, was killed in a clash with troops in his stronghold of Lower Dir early May.

The military says it has eliminated more than 1,800 militants, but troops are still clearing small pockets of resistance in several areas. The casualty count cannot be confirmed independently.

Human rights groups claim hundreds of civilians died in the onslaught.

Critics fear a resurgence of Taliban violence as only a few of the main militant leaders have been killed or detained during the operation which displaced nearly two million people. Fazlullah is among the fugitive leaders.

Sporadic clashes between soldiers and Taliban remnants picked up pace in August, with a couple of suicide bombings on security forces stationed in Swat.