(CNN) -- A U.S. drone crashed Saturday in Pakistan's tribal region, U.S. and Pakistani officials said.
The cause of the crash was unknown, but a U.S. official denied reports that the drone had been shot down.
Two Pakistani intelligence officials told CNN that witnesses in North Waziristan reported the crash near the village of Machikhel. The Pakistanis had only these witness accounts to go by, and were working to verify the crash and its causes with its own sources, the officials said.
North Waziristan is one of seven districts in Pakistan's tribal region and widely believed to be a sanctuary for the Haqqani network and other militant groups that fuel the insurgency across the border in Afghanistan. Two drone strikes killed 12 suspected insurgents in the region on February 16.
The United States does not publicly acknowledge its drone program, although President Barack Obama commented on such strikes in January and Defense Secretary Leon Panetta acknowledged the use of CIA predator drones in the region last year.
The CIA did not comment on Saturday's incident.
CNN's Pam Benson and Reza Sayah contributed to this report.