(AP) — A Pearl Harbor gate was closed for nearly two hours on Thursday after a military working dog smelled something suspicious during a routine inspection of a civilian contractor’s vehicle.

But explosive ordnance disposal technicians found nothing of concern and the scene was declared clear at 9:30 a.m., Joint Base Pearl Harbor-Hickam said in a statement. The gate reopened shortly after.

Military officials initially closed all gates to the base at 7:45 a.m. in response to what they called a “security incident.”

About 20 minutes later, the reopened all gates except the Halawa Gate, which is used primarily by commercial trucks during weekday daytime hours.

The National Park Service closed the nearby Pearl Harbor National Memorial Visitor’s Center, including tour boats to the USS Arizona Memorial, out of an abundance of caution.