391774 01: A MX or "Peacekeeper" missile sits at the entrance of Warren Air Force base, July 11, 2001 near Cheyenne, WY. 
Photo by Michael Smith/Getty

Air Force investigating drug abuse at Francis E. Warren Air Force base

Several U.S. airmen working at a Wyoming nuclear base have been suspended in an investigation of off-duty drug use, defense officials told NBC News.

Some of the 14 Air Force members under investigation worked security at the installation, the Francis E. Warren Air Force Base, the officials said. But none were directly connected to any nuclear weapons operations, they said.

No one has been charged.

Gen. Robin Rand, commander of Air Force Global Strike Command, said Friday that all 14 of the airmen held low ranks — airman, airman first class or senior airman. They are among 1,300 airmen in the missile security group at Warren.

The Air Force has not said what drug the airmen are suspected of using. The investigation began was a result of an airman’s tip, Rand said.

This article originally appeared on NBCNews.com.

Drugs

Air Force investigating drug abuse at Francis E. Warren Air Force base