The military, near the end of an offensive in the northwestern Swat Valley after two months of fighting, is preparing to launch a new drive in South Waziristan, where Pakistani Taliban chief Baitullah Mehsud is based.

The decision to go on the attack against the militants came after Taliban gains raised fears of the militants gradually taking over more of the country and even posing a risk to Pakistan's nuclear arsenal.

The campaign has broad public support and has also won the praise of close ally the United States, which needs Pakistan to go after the militants as it tries to defeat al Qaeda and stabilise Afghanistan.

Sunday's air strikes were on two villages in Laddah district, a Mehsud stronghold, and two militant compounds were destroyed, said a government official and residents.

"It was a heavy bombing. Two militant compounds and several houses have been completely destroyed. We're trying to get casualty figures," said the government official in South Waziristan's main town of Wana.

The official declined to be identified as he is not authorised to speak to the media about military operations.

The air strikes came after militants attacked an army and a paramilitary camp, both east of Wana, on Saturday night, killing two soldiers and wounding four, said the official.