There is an active shooter at the sprawling central Texas base of Fort Hood, a source at Fort Hood told CNN on Wednesday.
The situation is serious and sirens are going off, said the source, who spoke on the condition of anonymity.
A spokesman for the base said an "incident" was under way but declined for provide additional information.
Fort Hood's official Twitter feed asked that all personnel on post to shelter in place.
Source: Active shooter at Fort Hood - CNN.com