A US airstrike in the Afghanistan city of Kunduz reportedly killed nine members of the medical aid group Médecins Sans Frontières' (MSF) while the building of Doctors Without Borders suffered heavy damage as fighting continued between Afghan forces and the Taliban. 

The US airstrikes hit Kunduz in the early hours of Saturday and NATO said in a statement that the strikes "may have resulted in collateral damage to a nearby medical facility".

"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 Director of Operations Bart Janssens said on the website

At least 30 people are unaccounted for, Doctors Without Borders has said. 

"We do not yet have the final casualty figures, but our medical team are providing first aid and treating the injured patients and MSF personnel and accounting for the deceased. We urge all parties to respect the safety of health facilities and staff."

Kunduz fell to Taliban control earlier this week, but Afghan forces claimed to have retaken the northern city backed by US airstrikes. 

MSF and Doctors Without Borders have been treating hundreds of locals injured in the fighting since Monday.