He is believed to be the first special forces commander to switch sides in the war, and had received U.S. training, according to Agence France-Presse.
“He sent some of his comrades on leave and paid others to go out sightseeing, and then escaped with up to 30 guns, night-vision goggles, binoculars and a Humvee," Shuja ul-Mulkh Jalala, the governor of Kunar, told Reuters.
A manhunt is underway for the special forces commander, according to Reuters, and tribal elders also promised to help.
"We are trying our best to use elders' influence in that area to bring back all equipment," Jalala said.
The defection comes as Afghan and NATO forces deal with “insider attacks,” where Afghan soldiers attack supposedly allied forces.
Insider attacks have complicated the U.S. and NATO hand-off of security to the Afghans, which is scheduled to occur by the end of 2014.