Normal operations resumed at an Air Force base that was partially evacuated early Thursday, when potentially explosive material was detected during a routine inspection of a moving truck.
In a statement, the 66th Air Base Group said the truck had been cleared and personnel who had been ordered to leave Hanscom Air Force base earlier in the day were being allowed to return.
"However pallets from the truck, which contain potentially concerning residue, have been removed and will be taken to a specialized facility for testing," the statement continued.
The truck was stopped at about 9 a.m. at one of the entrances to the base, which is about 20 miles west of Boston.
There was no indication from authorities what type of material might have caused the concern. Several buildings were evacuated, and state police set up a 1,500-foot (457-meter) perimeter around the truck. An exit leading to the base from another route was also closed.
By early afternoon, TV news video showed officers removing items from the cargo area of the vehicle.
The truck is owned by Big Foot Moving & Storage. A woman who answered the phone at the company's Acton headquarters said, "We don't know what's going on."
No injuries were reported.
Hanscom Field, a civilian airport adjacent to the base, remained in operation throughout the incident, according to the Massachusetts Port Authority, which operates the commercial facility.
The Air Force base has been in existence since 1941 and has served as a major military research center.
— Angelica Carrillo (@acarrillonews) July 6, 2017