MIRAMSHAH: A triple US drone attack on a militant compound in Pakistan's northwestern tribal area killed at least 15 insurgents late Friday, security officials said.

Three unmanned aircraft fired a total of six missiles on Datta Khel village, some 35 kilometres (22 miles) east of Miramshah, the main town of North Waziristan tribal district, near the Afghan border, they said.

The initial strike on a house killed nine militants, three more were killed in a second attack when they drove to the site to recover dead bodies, and a third drone killed three more five minutes later, a senior security official in Peshawar told AFP.

“At least 15 militants have been killed in these three drone strikes and the drones fired a total of six missiles,” the official said.

Two security officials in Miramshah confirmed all the three strikes but told AFP that at least 20 militants have been killed, and one said the militants had gathered to send fighters to Afghanistan.

Datta Khel is considered to be a stronghold of Hafiz Gul Bahadur, a Taliban commander who is accused of sending fighters across the border to fight Nato troops in Afghanistan.

It was the first drone attack since Islamabad reached a deal with Washington to reopen land routes into Afghanistan after US Secretary of State Hillary Clinton said she was sorry for the deaths of 24 Pakistani soldiers in an air strike in November.

US officials consider the attacks a vital weapon in the war against extremists, despite concerns from rights activists over civilian casualties.

A similar attack in the region on Sunday killed six militants.

Islamabad is understood to have approved the drone strikes on al Qaeda and Taliban targets in the past. But the government has become increasingly vocal in its public opposition as relations with Washington have nosedived.