Kabul, October 17 (RHC)-- Doctors Without Borders says a U.S. tank has forced its way into the Afghan hospital destroyed by a U.S. airstrike, sparking concern the U.S. military may have destroyed evidence in a potential war crimes investigation.

The October 3rd airstrike on the hospital in Kunduz, Afghanistan, killed 12 medical staff and 10 patients. Thirty-three people remain missing.

Doctors Without Borders says the U.S. tank’s "unannounced and forced entry damaged property, destroyed potential evidence and caused stress and fear."

This comes as the Associated Press reports U.S. special operations analysts were gathering intelligence on the Afghan hospital in the days before the airstrike out of suspicion it was being used as a base for the Taliban.

The intelligence included maps of the regions with a circle drawn around the hospital. The White House has described the U.S. airstrike on the hospital as "a mistake."