The governor of Kunar province, Sayed Fazelullah Wahidi, said today that the three were killed in an overnight airstrike, which he claims was carried out by a drone in the Noorgaram area of the Dara-i Peach district.
The US-led alliance says it has no operational reporting to support the allegation made by Wahidi.
Kunar is on the border with Pakistan and has seen heavy fighting between Afghan government forces and insurgents.
Afghanistan has also blamed the Pakistani forces of shelling parts of the province near the frontier. Pakistan says militants retain safe havens in the area and stage cross-border attacks.