CBS Boston reports that the situation began around 9 a.m. Thursday, and the Massachusetts State Police bomb squad was called a short time later. An assessment of the truck and its cargo revealed there may be "potentially hazardous material", according to the Massachusetts State Police.
"Given the times we live in, we operate in an abundance of caution", he told reporters, adding that there were no suspects or arrests and none expected.
The Hanscom Air Force Base is 848 acres large and headquarters the 66th Air Base Group. The truck is owned by Big Foot Moving & Storage.
State police bomb squad commander Sgt. They have also closed the exit from Route 2A.
Those actions included the temporary closure of the base's Vandenberg Gate on Route 2A and evacuation of several nearby base facilities.
Massachusetts Gov. Charlie Baker said he has been briefed on the situation, but he is not able to say much because the investigation is still ongoing.
No injuries are reported and emergency personnel are on the scene.