Pease Air National Guard Base in Newington was placed briefly on lockdown late Tuesday morning after multiple reports of what sounded like gunfire.
Lt. Col. Gregory Heilshorn said the lockdown order was lifted and an all-clear signal given around 12:40 p.m., after law enforcement officers swept buildings and responded it was cleared.
Heilshorn did not have additional information to release regarding the cause of the gunshot sounds -- the Guard later said no gun shots were fired.
The 157th Air Refueling Wing at Pease Air National Guard posted on its Facebook page that the multiple reports came in at about 11:30 a.m. and Base security and local and state police responded. "After a thorough search, they determined there were no threats."
The Guard and responding agencies treated it like an active shooter scenario, per protocol.
From initial reports, the gunfire sounds were from the headquarters building at Pease Air National Guard, according to Heilshorn.
(This is a developing story. This post was updated with additional information from the 157th ARW at Pease.)