The armoured personnel carrier forced its way through the metal gate of the compound in Kunduz on Thursday afternoon and damaged the barrier, apparently unaware that Doctors Without Borders (MSF) staff including country director Guilhem Molinie were at the hospital, an AFP reporter saw.
Read: In policy reversal, Obama slows pace of US troop withdrawal in Afghanistan
The US delegation began negotiating with several foreign MSF doctors, insisting upon being allowed into the hospital as part of their investigation into the catastrophic October 3 strike that killed at least 24 people.
The discussions lasted for around an hour and a half, with the troops allowed to enter only after laying down their arms.
An MSF spokesperson confirmed the intrusion, adding it occurred "despite an agreement made between MSF and the joint investigation team that MSF would be given notice before each step of the procedure involving the organisation's personnel and assets".
"Their unannounced and forced entry damaged property, destroyed potential evidence and caused stress and fear for the MSF team," she said.
Read: America's 14 years in the Afghan quagmire
A NATO spokesperson said: "We are aware of the incident and are looking into what happened."
MSF has called for an impartial investigation into the strike on its hospital by the US, which killed at least 14 staff and 10 patients, with nine others still unaccounted for.
The attack caused global revulsion and caused MSF to close the hospital's trauma centre, seen as a lifeline in a war-battered region with scant medical care.
COMMENTS
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ