The CIA said its security personnel took a person into custody early Thursday after an engagement outside the intelligence agency's headquarters.
A CIA spokesperson confirmed security staff "engaged a person" outside the main gates, adding the individual was in custody.
The spokesperson declined to say whether gunfire struck the suspect or to disclose any other details.
NBC News reported earlier that the person was shot, citing a person with knowledge of the matter.
The incident occurred around 4:00 AM (0800 GMT), a Fairfax police spokesperson told ABC News.
The CIA closed the main gate at its Langley compound and directed employees to seek alternate routes.
The shooting incident came after two Israeli Embassy staffers were killed by a lone gunman in downtown Washington on Wednesday night. There was no indication the incidents were related.

Qatar busts two cells linked to Iran’s Revolutionary Guard
Jordanian airspace reopens after 'comprehensive review'
Iran vows to attack any ship trying to pass through Strait of Hormuz
Drones target fuel tanks at Oman’s Duqm Port
At least 42 civilians killed in Afghanistan in conflict with Pakistan, UN agency says