Washington ? The Air Force charged two Illinois Air National Guard pilots with involuntary manslaughter, aggravated assault and dereliction of duty in the mistaken bombing last April of a Canadian training exercise in Afghanistan that killed four soldiers and wounded eight.

Maj. Harry Schmidt, a senior pilot with 13 years of military flying, and Maj. William Umbach, commander of their F-16 squadron, were accused Friday of poor airmanship and judgment and failing to follow procedures.

The pilots may face courts-martial. Each was charged with four counts of involuntary manslaughter, eight counts of aggravated assault and one count of dereliction of duty. If convicted on all counts, each could be sentenced to a maximum of 64 years in confinement and forfeit all pay and allowances.

“These charges are only accusations,” a Pentagon statement said. “Both officers are presumed innocent.”

In a statement issued on Schmidt’s behalf, his civilian lawyer in Washington, Charles Gittins, said Schmidt regretted the deaths and injuries but believed at the time that the Canadians were firing at him and Umbach.

“Maj. Schmidt also regrets that the Air Force has taken the unprecedented step of charging a combat aircrew involved in a combat mission criminally where those officers were required to make split-second life or death decisions without benefit of detached and calm reflection,” he said.

The men’s military lawyers are based in Germany and could not be reached for comment Friday.