Via NBC:

Evacuations were ordered Friday after a driver tried to gain access to New Jersey’s Picatinny Arsenal and security guards noticed something suspicious about the vehicle, officials say.

Two sources familiar with the investigation tell NBC 4 New York the driver was taken into custody.

The driver tried to enter the Morris County Army installation at 11:30 a.m., authorities said. It wasn’t immediately clear what security guards perceived to be suspicious about the vehicle, but they were treating it “as if it were an explosive threat,” the arsenal said in a statement.

The gate was locked down and employees were instructed to leave their posts shortly before 2 p.m. as robots and explosive detection devices assessed the vehicle.

The immediate area, including businesses near the entrance, was evacuated. Route 15 from Berkshire Valley Road to Route 80 was closed to assist in the investigation, and photos showed extensive traffic delays in the area near the base.

Picatinny Arsenal is a research and manufacturing facility in Rockaway Township. About 5,000 people work at the arsenal, which provides ammunition, weapons and other materials to all branches to the U.S. military.