Police officer dies following violence outside Pentagon, officials say

The incident happened at the metro transit station for the Pentagon, in northern Virginia.

A police officer died Tuesday following a violent incident that included gunfire outside the Pentagon building, according to several news reports.

The incident is the subject of an ongoing investigation, and no details immediately will be released, Defense Department spokesman John Kirby said during a Tuesday afternoon press conference at the Pentagon. 

The scene is secure, and there is no ongoing threat to the public, said Woodrow Kusse, the Pentagon police chief, who spoke during the same briefing.

Officials did not confirm whether the violence included stabbing, as some outlets reported; nor whether the officer died following a knife attack.

At about 11 a.m., the Pentagon was put on temporary lockdown – following reports of multiple gunshots near a platform by the building’s metro transit station, in northern Virginia, according to the Associated Press.

The Pentagon Force Protection Agency confirmed in a tweet that the U.S. military headquarters was  on lockdown and asked the public to avoid the area.

The Arlington County Fire Department reported "multiple patients," but how many patients there are and the extent of the injuries is still unknown.

The Pentagon Force Protection Agency, which oversees the security of the Pentagon, did not respond to CNN’s request for comment.

Pentagon Force Protection Agency Chief Woodrow Kusse is expected to brief reporters Tuesday afternoon on the incident, with Pentagon press secretary John Kirby to provide more information.