The Walter Reed Medical Center, which is located at the US Navy base just in Maryland, is on lockdown Wednesday morning as officials were investigating a bomb threat.

Staff and those visiting the base at Bethesda, Maryland, were asked to take refuge in place, while the base’s gates were closed to non-emergency traffic, according to tweets posted by Walter Reed accounts and the base. 

According to the Naval Support Activity Bethesda base’s Twitter feed, the anonymous threat, which was received at 8:45 am, warned there was a bomb in or near Building 10 at Walter Reed.

“An active shooter threat also was initially made. There is no indication of a shooter,” officials said.

K-9 teams got onto clearing buildings two hours after the phone call. 

“All personnel and beneficiaries are directed to stay clear of Walter Reed Bethesda,” Walter Reed officials said.

Presidents of the United States and other government officials visit Walter Reed, a military hospital, for treatment. Former President Donald Trump was admitted there when he was infected with COVID-19 last year. 

“A hazard exists at Walter Reed National Military Medical Center. All personnel and beneficiaries are directed to stay clear of Walter Reed Bethesda,” the hospital’s Twitter account stated.

In a text message to CNBC, Kai Hibbard, a veteran at Walter Reed, said she arrived for an appointment for her husband and was ready to drive off the facility when “everything locked down.”

“Loudspeakers announced that all personnel should get to the nearest building and shelter in place until the all clear is given,” said Hibbard. 

She had just found out about the threat through social media. 

“My husband and I are safe, sheltered in place and just watched the (what I assume is) bomb dog and [its] handler go through the parking lot,” Hibbard added.