US officials strongly rejected allegations in an independent study that a covert drone war in Pakistan has killed large numbers of civilians, saying the numbers are "way off the mark."
US officials on Friday slammed the London-based Bureau of Investigative Journalism report's finding that there had been many more CIA attacks on alleged militant targets and far more civilian deaths than previously reported.
The report said that bombing raids by unmanned aircraft, designed to target al Qaeda and Taliban militants, had killed up to 168 children in Pakistan over the last seven years.
"The numbers cited by this organisation are way off the mark," said a senior US official, who spoke on condition of anonymity.
"In the past year, in the neighborhood of 600 militants -- including over two dozen terrorist leaders -- have been taken off the battlefield.
"In that same period of time, we can't confirm any noncombatant casualties," the official told AFP in an email.
A second US official, who also asked not to be identified, dismissed the report as unfounded, saying: "The numbers are wrong."
The officials said intelligence agencies took precautions to avoid killing civilians and that the robotic aircraft --equipped with missiles, video cameras and sensors -- can linger over a target to ensure accuracy.
"This is a weapon -- fueled by good intelligence -- that allows us to counter an urgent and deadly threat in otherwise inaccessible places," said the first official.
"And it's far more precise than conventional ground operations. What's the alternative to this kind of rigor, assuming the United States and its allies are unwilling to allow al Qaeda and its friends to plot and murder freely?"
The London-based group said 291 CIA drone strikes had taken place in Pakistan since 2004, eight percent more than previously reported, and that under President Barack Obama there had been 236 -- one every four days.
But the official said the report's numbers had not been confirmed.
"Credible reports of civilian deaths are taken into account, period. If large numbers of innocent people were being killed, the Pakistanis wouldn't stand for it. Neither would we. That's the reality," the official said.
US officials also cast doubt on one of the report's sources, Mirza Shahzad Akbar, a Pakistani lawyer who is suing the Central Intelligence Agency on behalf of civilians who say they lost loved ones in drone strikes.
The official said there were concerns about the lawyer's possible links with Pakistani intelligence, as Akbar had publicly named the CIA's undercover station chief in the country.