KABUL, Afghanistan — U.S. defense officials are to tell Congress Wednesday that supposedly friendly Afghanistan security forces have attacked U.S. and coalition troops 45 times since May 2007, for the first time laying out details of attacks that have killed 70 and wounded 110.
Defense officials say that in most cases the Afghans acted out of personal motivation and were not controlled by insurgent groups.
The second most common circumstances involve insurgents impersonating Afghan security forces.
The revelations were made in testimony prepared for delivery Wednesday to the House Armed Services Committee. It was obtained by The Associated Press.
The latest such killing happened Wednesday when an Afghan soldier shot and killed a NATO service member in southern Afghanistan, officials said.
The news came as The Times newspaper, which operates behind a paywall, reported Wednesday that a secret U.S. military report said the Taliban, backed by Pakistan, are set to retake control over Afghanistan after NATO-led forces withdraw from the country.
Lt. Col. Jimmie Cummings, a spokesman for the NATO-led International Security Assistance Force (ISAF), confirmed the document's existence but said it was not a strategic study of operations.BBC: Secret report reveals Pakistan-Taliban ties
Insider attacks by Afghan security forces have been on the rise, punctuated by the Jan. 20 shooting of four French troops by an Afghan soldier that prompted France to threaten to withdraw its forces earlier than planned.
International forces and the Afghan army disagreed on exactly what happened in Wednesday's killing.
Cummings, the ISAF spokesman, said Afghan soldiers detained the gunman after he attacked NATO troops Tuesday night. The coalition gave no other details.Video: Afghan president to meet with Taliban (on this page)
Afghan National Army commander Sayed Malluk confirmed the shooting, which he said happened during a night patrol in Helmand province's Marjah district.
But he said the Afghan soldier, who has been in the army for more than two years, told investigators the shooting was an accident.
After the French soldiers were killed, French President Nicolas Sarkozy announced that France would speed up the exit of its troops from Afghanistan and that it would ask NATO to hand over all combat operations to Afghan forces in 2013 instead of by the end of 2014.Afghan women keep pushing to have voices heard
Sarkozy at the time said the attacker was a Taliban infiltrator, but Afghan and NATO investigators have said it was too early to know his motivation.
The rising number of attacks by supposed friendly Afghan forces has prompted speculation that Taliban insurgents or sympathizers may be infiltrating national army and police as they rapidly expand to meet a 2014 target for Afghan forces to take over security and most international troops to leave.
The number of attacks on international troops — by Afghan soldiers, police or insurgents wearing their uniforms — rose sharply last year to 17, up from six in 2010.Story: Afghan woman slain for giving birth to daughter
But NATO spokesman Cummings said Wednesday the rising number of attacks doesn't point to any pattern.
"We feel they're isolated cases," he said. "There's no indication these incidents are linked or part of any coordinated effort."
Cummings said that the 130,000-strong international force works daily with more than 300,000 Afghan security personnel, mostly without problems.
He said that NATO is satisfied with Afghanistan's vetting process for army recruits.US, Taliban talks on prisoner swap falter
Cummings said the document published by The Times was "classified" and "a compilation of Taliban detainee opinions."
"It's not an analysis, nor is it meant to be considered an analysis," he said.
Nevertheless, it could be interpreted as a damning assessment of the war, now dragging into its eleventh year and aimed at blocking a Taliban return to power, or possibly an admission of defeat.
It could also reinforce the view of Taliban hardliners that the group should not negotiate peace with the United States and President Hamid Karzai's unpopular government while in a position of strength.
Strained ties with West
The document cited by Britain's The Times also said that Pakistan's powerful security agency, the Inter-Services Intelligence (ISI), was assisting the Taliban in directing attacks against foreign forces.
The allegations drew a strong response from Pakistani Foreign Ministry spokesman Abdul Basit. "This is frivolous, to put it mildly," he told Reuters. "We are committed to non-interference in Afghanistan."
The Times said the "highly classified" report was put together by the U.S. military at Bagram air base in Afghanistan for top NATO officers last month. The BBC also carried a report on the leaked document.
Large swaths of Afghanistan have already been handed back to Afghan security forces, with the last foreign combat troops due to leave by the end of 2014.
But many Afghans doubt their army, security forces or police will be able to take firm control of one of the world's most volatile countries once foreign combat troops leave.
The U.S. Embassy in Kabul declined to comment on the report.
The accusations will likely further strain ties between Western powers and Islamabad, which has long denied backing militant groups seeking to topple the U.S.-backed government in Kabul.
The Associated Press and Reuters contributed to this report.