MIRANSHAH, Pakistan (Reuters) - At least five people were killed on Friday in a missile attack by a suspected U.S. drone in Pakistan's North Waziristan region, in a stepped up campaign against militants near the Afghan border.
U.S.-controlled Predator aircraft have struck several sites used by al Qaeda operatives in Pakistan this year, most recently on Thursday when four low-level al Qaeda-linked militants were killed in the same region, security officials said.
The Friday attack was on a house in the Guvrek area, near the border with Afghanistan.
"Two drones were flying in the area. They fired three missiles," said a witness who declined to be identified.
An intelligence official said five militants were killed while another said the toll could rise. It was not immediately known if any senior al Qaeda figures were among the casualties.
Another intelligence official, however, said those killed were civilians including four children and a woman.
On Wednesday, U.S. forces carried out a pre-dawn helicopter-borne ground assault on the village of Angor Adda in the nearby South Waziristan in the first known incursion into Pakistan by U.S.-led troops since the 2001 invasion of Afghanistan.
Officials said 20 people, including women and children, were killed in the attack which sparked fury in Pakistan.
Pakistan is a staunch ally in the U.S.-led war on terrorism but rules out encroachment by foreign troops onto its terrority.
It condemned the Wednesday attack and summoned the U.S. ambassador to lodge a protest. Parliament called for border raids to be repulsed.
General Tariq Majid, chairman of Pakistan's Joint Chiefs of Staff Committee, said cross-border strikes such as the one on Wednesday would alienate ethnic Pashtuns, who live on both sides of the border, and be counter-productive.
"Pakistan reserves the right to appropriately retaliate," he told visiting German Defence Minister Franz Josef Jung.
The anger over U.S. attacks comes in the run-up to a presidential election.
Asif Ali Zardari, widower of assassinated former prime minister Benazir Bhutto, looks set to become president on Saturday in an election by legislators to chose a replacement for Pervez Musharraf, who resigned last month.
Zardari is seen as close to the United States but the anger over U.S. strikes is not expected to hurt his chances of victory.
However, ordinary Pakistanis, many of whom harbour anti-American feelings, will be expecting him to take a stand against the U.S. attacks.
Washington says al Qaeda and Taliban militants lurk in sanctuaries in northwest Pakistan's ethnic Pashtun tribal areas on the Afghan border, where they orchestrate attacks in Afghanistan and Pakistan and plot violence in the West.
Additional reporting by Alamgir Bitani