The Delaware National Guard increased security Wednesday at its air base after different vehicles approached its gate this week, then left.
Officials said there have been five incidents at the Air National Guard Base near Wilmington in which vehicles have approached the main gate and the occupants asked for directions. Col. Len Gratteri, a Guard spokesman said that in at least one case, a vehicle turned around before reaching the main gate.
It's not uncommon for people to get lost and ask for directions, Gratteri said. It was the frequency that prompted heightened security.
"That's the activity we think is suspicious. ... Is it a coincidence, or is it a part of something else?" he said.
Gratteri said he does not believe the same vehicle or same individuals were involved each time. Investigators are reviewing security camera footage from the base, which is part of a dual-use facility that includes New Castle Airport.
The base is home to a fleet of eight C-130 military cargo aircraft and more than 1,110 personnel, about 300 of them full-time. Vice President Joe Biden, who is from Delaware, has flown to the base in the past on Air Force Two.
Officials with the base's 166th Airlift Wing posted a message on their website, instructing personnel on how to spot and report suspicious activity. It detailed categories of suspicious behavior, including surveillance and attempts to test security or gain access to a base.
Base officials also have shared information with the Air Force and with local law enforcement agencies.
Sgt. Richard Bratz, a spokesman for the Delaware State Police, said his agency has increased patrols at 16 National Guard facilities throughout the state. However, he said the agency has not received any credible threats.