Marjan Haqmal, police chief of Nad Ali district in Helmand province, said the Russian-made aircraft probably went down because of a technical malfunction.
NATO confirmed that a civilian helicopter crashed Monday in southern Afghanistan. It said the site of the crash has been secured and that coalition forces are trying to gather more information about what happened.
The alliance did not provide information about casualties.
Dozens of Russian-built cargo helicopters are used by contractors working for the NATO-led coalition.
The coalition relies heavily on helicopters or airdrops to deliver food and other supplies to remote outposts in order to avoid using roads that are frequently mined by the insurgents. Transport aircraft are also frequently used for airdrops to isolated bases.
The Taliban have few dedicated anti-aircraft weapons, but they have damaged or destroyed dozens of helicopters and fixed-wing aircraft using automatic rifles and other infantry weapons. In August, militants shot down a U.S. Chinook transport helicopter, killing 30 U.S. special operation troops, a translator and seven Afghan commandos.