Arnold Gate of the Anacostia-Bolling joint military base in Washington, Wednesday, April 17, 2013.

Alex Brandon | AP

A lockdown at a U.S. military base in Washington, D.C., was lifted Friday after authorities detained a possibly armed individual who had entered the campus.

The all-clear announcement came at 2:50 p.m., more than two hours after Joint Base Anacostia-Bolling alerted people that the individual, initially described as a Black man with a medium-build carrying a Gucci bag, was on base.

The suspect had been detained by security forces at the base and would be transferred to the Metropolitan Police Department, whose officers were on the scene, a spokesman for the base told CNBC. The spokesman declined to say if the person surrendered willingly or if he was armed at the time he was detained.

Earlier, a spokeswoman for the MPD told CNBC that the department had received a phone call at 12:04 p.m. regarding the sound of gunshots being heard at a location east of the base.

No victims were been identified, the spokeswoman said.

MPD said they would only verify the person was male.

A social media account for the base at 12:37 p.m. first announced the potential threat.

“LOCKDOWN LOCKDOWN LOCKDOWN,” said a post on the base’s Facebook page.

“If you encounter the individual and have a safe route, RUN. If you do not have a safe route to run, HIDE. Barricade your door, turn off the lights and your cell phone ringer, and remain silent. If you are hiding, prepare to FIGHT,” the post said.

An update later described the individual as a Black man with a medium build and “dreads that are mid-back in length.” The person was wearing blue or green pants and a white tank top, and he may have been carrying a bag, according to that Facebook post.

That update, which came more than an hour after the lockdown order was posted, advised people to “continue to shelter in place.”

About 15 minutes beforehand, the Facebook page had alerted people to be on the lookout for two individuals: one a Black male with medium build “with dreads” and “wearing ripped blue jeans,” and the other a Black man wearing green pants and a white top who “may be injured.”

That was revised to just one person in subsequent posts.

Google Earth viewo of Anacostia-Bolling Air Force Base, DC.

Google Earth