A lockdown at Travis Air Force base was lifted Wednesday afternoon after reports of an active shooter turned out to be false, law enforcement officials told NBC News.

According to sources, a call about an active shooter from the base was a false alarm. There were no injuries reported.

Travis Air Force base officials tweeted at 5:20 p.m. that "emergency personnel responded to reports of gun shots @ the Base Exchange. It was determined to be a false alarm. Lockdown is lifted."

A Facebook post around 3:30 p.m. advised people to avoid the area so emergency responders can do their jobs. People were also urged to shelter in place due to a "real world incident" and asked to lock doors and windows.

The facility's main gate was closed, Fairfield police wrote on Twitter, and social media users reported an active shooter situation.



Scenes from an NBC-affiliate chopper showed people walking around at the base, a sprawling campus located in Solano County. Some people were holding hands as they were being escorted to safety, and police cars dotted the parking lot.



A simulated security drill was scheduled to take place Wednesday and Thursday, but Travis Air Force base officials said on social media the security incident was unrelated to it.



Dozens of parents of military personnel who are based out of Travis posted on the base's Facebook page, looking for information.



No further information was immediately available.