The crash occurred as the plane, assigned to the 774th Expeditionary Airlift Squadron, was taking off around midnight from an airfield in Jalalabad.
The dead included the six crew members, all American armed forces personnel; five civilian contractors working for the American-led military mission in Afghanistan; and three Afghan civilians.
In Washington, the Pentagon said that the crash was under investigation and released no further information.
A spokesman for the Taliban, Zabihullah Mujahid, said Friday on Twitter that the militants had shot the plane down, Agence France-Presse reported. The Taliban have made false assertions about battlefield successes in the past, and the spokesman offered no proof of the claim.
A press official with the U.S.-led coalition in Afghanistan said later Friday that there had been no enemy activity in the area at the time of the crash. The coalition often makes such statements after a crash, but they have sometimes proved to be incorrect after further investigation.
The C-130 is a four-propeller transport aircraft used to haul troops as well as military equipment in and around war zones. Manufactured by Lockheed Martin, it is the short- and medium-range workhorse of the military, with a respected safety record. The first C-130 flight was in 1954, and the planes have played a role in every American war since.
Aside from transport, C-130s are used for refueling, surveillance and firefighting. In 2012, a North Carolina Air National Guard C-130 crashed while battling a forest fire in the Black Hills of South Dakota.
Last year, a C-130 operated by the Algerian military crashed in a mountainous region of Algeria. More than 70 people were killed.
Stephanie Stinn, a spokeswoman for Lockheed Martin, referred questions to the Air Force.