LADDAH, Jan 17 At least 20 suspected militants were killed in a pre-dawn US drone attack on a residential compound in Shaktoi area of South Waziristan on Sunday, official sources said.

Unmanned drone aircraft had attacked the same area on Thursday and 16 militants were reported to have been killed.

That attack had sparked reports that Hakimullah Mehsud, the chief of the Pakistani Taliban, had been killed. But the militants denied the report and released two audio messages of their leader.

According to officials, some foreigners were among the 20 militants killed in Sunday's attack. However, the claim could not be verified from independent sources.

Official sources said the US drone fired three or four missiles at around 4am on the compound owned by one Pir Gul, adding that two local commanders and four Uzbeks were among the dead.

Taliban neither confirmed nor denied the claim.

Agencies add Security officials said US drones appeared to be tracking Hakimullah in a surge in strikes by unmanned spy planes. It was the 10th US drone strike to hit the tribal belt this month.

“The target was a militant compound,” said a security official in the area.

“Twenty militant deaths have been confirmed.”

An intelligence official said that militants had ringed the demolished compound in the remote and mountainous area and were digging out the bodies.

“The drones are apparently tracking and targeting Pakistani Taliban chief Hakimullah Mehsud whose presence is frequently reported in the area.”