UPDATE — 11:00 A.M. EST: A driver who crashed his vehicle into the front gates of the Naval Station Great Lakes is in police custody and undergoing questioning. “The area is being swept by military working dogs. Several buildings have been evacuated,” said a spokesperson for the navy base. Read Breitbart News’ original report below: 

The Naval Station Great Lakes is on lockdown Friday as law enforcement search for a “gate runner” ahead of a graduation ceremony slated to take place at the Illinois station.

In a Facebook post, the base ordered personnel to “take cover in nearest building or structure,” while individuals inside were asked to “run, hide, fight” and await further instruction.

Speaking to NBC Chicago, Lake County Sheriff Spokesman Sgt. Christopher Covelli said a vehicle rammed the base’s front gate and that officers were conducting a search for a person within the station.

“No one was harmed and no property was damaged,” said a public information officer for the base.

Due to the incident, the graduation ceremony was pushed back to 10 a.m. local time instead of 9 a.m. “due to a variety of circumstances,” the officer added.

There are no additional details known at this time.

This story is developing. Check Breitbart News for updates.