Update as of 10:21 p.m. ET: The guard shot at the U.S. Census Bureau headquarters in Washington D.C. on Thursday evening has died of his injuries, according to a report from NBC Washington

Update as of 9:25 p.m. ET: Police have given the all-clear at the U.S. Census Bureau headquarters, where earlier tonight a gunman shot and critically injured a security guard.

The suspect police believe to be responsible for the shooting was apprehended, after a vehicle that matched the desription of the gunman's was seen in northeast D.C. After a chase, the suspect engaged officers in a gunfight at the 1100 block of H Street, WJLA reported.

The suspect was shot in the head, but is not dead, Police Chief Cathy L. Lanier told the Washington Post. An officer sustained a leg wound in the exchange of fire.

The guard wounded earlier tonight remains in critical condition at an area hospital.

Original story below

A gunman shot and critically injured a security guard at the Census Bureau headquarters near Washington, D.C., Thursday, leading to a massive police operation in the area, according to multiple media reports.

Prince George's County Fire Department spokesman Mark Brady told the Associated Press that the guard, who was on duty at the gates of the campus in Suitland, Maryland, was shot in his upper body and was taken to a local hospital in extremely critical condition.

The Washington Post reported the presence of approximately two dozen military-clad officers with rifles at the campus. Officers were seen sweeping through parking garages around 7:45 p.m. ET. Three small explosions were heard shortly afterwards, the paper added.

Unconfirmed reports suggest that the gunman may be barricaded inside the Census Bureau facility, though there is no official confirmation of this.

Washington, D.C., police were also involved in a high-speed pursuit, involving a man who shot at them shortly after the Census Bureau shooting. WTOP reporter Shomari Stone tweeted that the man involved in the chase crashed, and was shot by police. It is unknown if the chase and subsequent shooting has anything to do with the Census Bureau shooting.

Reports on social media suggest that a reporter with WRC-TV has said two police sources have informed him that the man shot following the chase is the Census Bureau shooting suspect, but there is no official confirmation of this.

This is a developing story – check back for updates.