JACKSONVILLE, Ark. - Little Rock Air Force Base went on lockdown Wednesday amid reports of a suspicious person, though military officials have offered few details about the incident.

No one is allowed to enter or leave the base during the lockdown, which began at 11:45 a.m. Spokeswoman Lt. Mallory Thornton said the base took the step "in the interest of protecting all base members." People who live on base were urged to stay indoors, and visitors were asked to not come to the front gate.

Thornton declined to provide further information about what led to the lockdown, saying more information will be released later Wednesday. Gates allowing access to the base were closed and a line of vehicles stretched for a quarter-mile outside of the base, which is located about 15 miles northeast of Little Rock.

Emergency crews were on the scene, and sirens could be heard over loudspeakers outside the base's entrance. The base had been conducting emergency response exercises, but officials said Wednesday's incident was not part of the drill.

The base specializes in the C-130 cargo airplane and is home to the 19th Airlift Wing, the 314th Airlift Wing and the 29th Weapons Squadron. The Arkansas Air National Guard's 189th Airlift Wing is also located on base.