Three U.S. missile strikes hours apart killed 18 people in a militant stronghold near the Afghan border in northwest Pakistan on Saturday, two Pakistani intelligence officials said.
At least nine people were killed in the first strike when missiles destroyed a moving vehicle in the North Waziristan tribal region, the officials said.
Two hours later drones fired more missiles that struck people who had gathered to retrieve the bodies, killing five. A third strike Saturday evening once again targeted a moving vehicle in the Mohammed Khel area of North Waziristan, killing four people, they said.
The identities and nationalities of the 18 slain men were not immediately known, the officials said. They spoke on condition of anonymity because they were not authorized to speak to reporters.
The latest three strikes came a day after four missiles struck a militant convoy, killing eight suspected militants.
An additional 35 were killed in similar strikes on Monday and Tuesday.
A total of 118 such strikes, carried out by unmanned aircraft, were launched in 2010 in the northwest border region, killing up to 2,100 people, most of them militants, according to the Washington-based policy think-tank New America Foundation.
Nearly all have hit North Waziristan.
Pakistan's government publicly protests the airstrikes, saying they violate the country's sovereignty and anger tribesmen whose support is needed to fend off extremists. But Islamabad is widely believed to secretly support the attacks and provide intelligence for at least some of them.