The attack on the MSF hospital came amid fierce clashes in and around Kunduz on Saturday, as Taliban fighters who seized the city six days ago try to hold out against government forces.

Government troops recaptured most of the city on Thursday.

"We are deeply shocked by the attack, the killing of our staff and patients and the heavy toll it has inflicted on healthcare in Kunduz," MSF said in a statement.

It said 30 staff were still unaccounted for in addition to the three killed, adding that at the time of the bombing 105 patients and their caretakers, in addition to more than 80 international and Afghan staff, were present at the hospital.

Possible US strike

The group said the hospital was partially destroyed in the overnight bombing, which it described as an "aerial attack." It was unclear whether the attack was carried out by Afghan forces or the US military.

US forces confirmed that they conducted an airstrike on Kunduz at the time, with a spokesman saying that it "may have resulted in collateral damage to a nearby medical facility." He said the incident was under investigation, adding that it was the 12th airstrike carried out by the US "in the Kunduz vicinity" since Tuesday.

The US military has been giving aerial support to Afghan government troops who are trying to root out the remnants of Taliban fighters who took the city Monday in the biggest victory of their nearly 14-year insurgency.

tj/rc (AP, Reuters)