Pease Air National Guard Base in New Hampshire was locked down for an hour Tuesday after multiple reports of gunshots, but the alert was lifted after nothing was found amiss, officials said.

“Local law enforcement has swept the base, and they found nothing,” spokesman Lt. Col. Greg Heilshorn said.

Reports of what sounded like shots fired originated from the Guard’s headquarters building at the base in Portsmouth, he said. The building is just inside the main gate.

“So we haven’t even confirmed whether that was actually the case or something else entirely different,” Heilshorn said.

He added: “Treating it with the utmost caution, we responded as if it were an active shooter scenario. Local law enforcement responded and swept the base building by building.”

The lockdown started at 11:22 a.m., and the base issued an all-clear announcement over its loudspeaker system at 12:37 p.m., The Portsmouth Herald reported.

There are no reports of injuries, New Hampshire Air National Guard Col. Bill Davis said.

(AP)