WASHINGTON - American soldiers and airmen who killed and wounded dozens of civilians in a strike on an Afghanistan hospital violated U.S. rules of engagement and have been suspended as they await disciplinary action that could include criminal charges, military officials said Wednesday.

Briefing reporters on the results of two investigations, Gen. John Campbell, the U.S. commander in Afghanistan, described an egregious series of human and technical failures that led a U.S. warplane to destroy a medical charity's hospital in northern Afghanistan last month. Campbell and other officials would not say how many people had been removed from their jobs or whether anyone higher in the chain of command would be disciplined.

'Human error'

"This was a tragic but avoidable accident caused primarily by human error," Campbell said. He left open the possibility that disciplinary action, which has yet to be determined, could include courts-martial.

Christopher Stokes, general director of Doctors Without Borders, whose hospital was attacked, said the U.S. military's statements Wednesday left his group with more questions than answers.

"The frightening catalog of errors outlined today illustrates gross negligence on the part of U.S. forces and violations of the rules of war.," Stokes said.

Officials said the crew of an AC-130 gunship had been dispatched to hit a Taliban command center in a different building, 450 yards away. However, hampered by problems with their targeting sensors, the crew relied on a physical description that led them to begin firing at a hospital run by the Doctors Without Borders, a medical charity, even though they saw no hostile activity there.

Chances were missed

Many chances to avert the error were missed, officials said.

Asked whether the scale of the air attack - even if it had hit the correct target - was justified under the U.S. rules of engagement and international laws governing armed conflict, the actions taken by the U.S. aircrew were "not appropriate" to the threat they faced, said Campbell's spokesman, Brig. Gen. Wilson Shoffner. He declined to be more specific.

Campbell and Shoffner said that neither the Special Forces commander who called in the strike at the request of Afghan forces, nor the aircrew, was aware that a hospital was being hit until it was too late. The generals did not address claims by Afghan officials that the hospital had been overrun by the Taliban.