Separately, a roadside bomb Sunday killed three soldiers in Pakistan's Khyber tribal district, where a retaliatory operation by the security forces left three suspected militants dead.

The remote-controlled blast struck a vehicle carrying troops from the Frontier Corps paramilitary force as it passed through the Mandikas area close to the Afghan border.

'Two soldiers died at the scene whereas four others were wounded,' said Rahat Gul, an official in the local administration. One of the injured succumbed to his wounds in the hospital, he added.

Government forces cordoned off the area after the explosion and killed three militants in gunfights, the Urdu-language Geo News television channel reported.

Meanwhile, 10 Taliban fighters died and 20 were injured when helicopter gunships pounded militant positions in South Waziristan, another stronghold of former Taliban chief Baitullah Mehsud, who died in a US drone attack early last month.

'The limited airstrikes were carried out in Ladha area,' said an intelligence official who further said that the ground troops demolished 10 houses of the suspected rebels.

Mehsud led Tehrik-e-Taliban Pakistan (TTP), an umbrella organization of more than a dozen extremist organisations, including Fazlullah's group in Swat.

The TTP fighters have chosen Hakimullah Mehsud, a young Taliban commander who is from Baitullah's Mehsud tribe, as their new chief.