WASHINGTON

A recent airstrike on a hospital in Afghanistan that killed 22 victims was a “mistake”, the top U.S. commander in Afghanistan said Tuesday. 

The U.S. decided to conduct the airstrike in northern Afghanistan but "mistakenly struck" a hospital in Kunduz, said Gen. John Campbell, the top commander of U.S. and NATO forces in Afghanistan. 

"We would never intentionally target a protected medical facility," Campbell said. "We continue to make extraordinary efforts to protect civilians."

Campbell’s remarks came during testimony before the Senate Armed Committee. The hearing is one of two congressional hearings for the general this week that was scheduled before the deadly airstrike Saturday.

On Monday, Campbell had said that the airstrike was requested by Afghan forces who reported being under Taliban attack.

Among the victims killed was staff with the medical aid group Doctors Without Borders that operated the clinic.

The group said that while the U.S. attempts to shift blame, the American military is responsible for the attacks and deaths.

"Their description of the attack keeps changing - from collateral damage, to a tragic incident, to now attempting to pass responsibility to the Afghanistan government," said Christopher Stokes, the group’s general director. "The reality is the U.S. dropped those bombs."

The U.S. said three separate investigations have been launched in the wake of the attacks. 

"I ensure you that the investigation will be thorough, objective and transparent," said Campbell.