WASHINGTON — President Obama called the head of Doctors Without Borders Wednesday to apologize for the errant US airstrike on the group’s hospital facility in Kunduz, Afghanistan, which killed 22 people.

The nonprofit has called the attack a war crime and is demanding an independent investigation.

Among the victims were 12 of the organization’s staffers.

Obama “offered his heartfelt apology,” White House press secretary Josh Earnest said.

The group’s president, Joanne Liu, said in Switzerland, “If we let this go as if it was a nonevent, we are basically giving a blank check to any countries who are at war.”