A NATO rescue team dropped by helicopter in remote mountains of northern Afghanistan early on Saturday freed four aid workers, including two doctors, who had been seized by the Taliban last month, the alliance said. 

The aid workers, employed by Swiss-based Medair, were en route to flood-stricken parts of Badakhshan province when they were kidnapped. 

NATO forces entered the area under cover of darkness and after confirming the presence of the hostages, carried out a successful raid to free them, Lieutenant Commander Brian Badura, a spokesman for the NATO-led International Security Assistance Force (ISAF)

The rescue team suffered no casualties in the operation, Badura said. The kidnappers were armed with heavy machine guns, AK-47 assault rifles, and rocket-propelled grenades. 

Shamsul Rahman Shams, the deputy governor of Badakhshan, said five men who were holding the aid workers were killed in the operation.