WASHINGTON (AP) — The Marine Corps says seven Marines based in North Carolina were killed and several injured in a training accident at the Hawthorne Army Depot in Nevada.

According to a statement from the 2nd Marine Expeditionary Force at Camp LeJeune, N.C., the cause of the accident that happened shortly before 10 p.m. Monday is under investigation.

The injured were taken to area hospitals for treatment and further evaluation.

The identities of those killed were not released pending notification of their families and a 24-hour waiting period after that.

The Hawthorne Army Depot stores and disposes of ammunition. The facility is made up of hundreds of buildings spread over more than 230 square miles.