There was a fair amount of conflicting information in the past hour or so about a situation near the Pentagon, so we waited a bit to see how things played out.
Based on what FBI Special Agent Brenda Heck and U.S. Park Police Sgt. David Schlosser just told reporters, it appears:
-- A "suspicious" man was apprehended before dawn in Arlington National Cemetery, which is near the Pentagon.
-- The investigation led authorities to a red, 2011 Nissan parked somewhere near the Pentagon.
-- Bomb disposal technicians found no "significant explosive related items" in the vehicle, Heck says.
-- There was a "nonexplosive, unknown material which will require further investigation" found in the man's backpack, according to Heck.
-- Authorities believe the man was alone.
-- Nothing has been detonated, either in the vehicle or from the man's backpack. Earlier, some local news outlets reported they had been told that the vehicle had been blown up.
As for the scene on the highways near the Pentagon, "road closures created a traffic nightmare for commuters," local WTOP reports.
Update at 2:39 p.m. ET. The Man Arrested:
The FBI's Washington Field Office says Yonathan Melaku, 22, of Alexandria, VA., was the man detained this morning. The office confirms all the details we reported earlier. They add that the Marine Corps say Melaku joined the Marine Corps as a reservist in Sept. of 2007. He has not deployed overseas and that he has "previously been awarded the National Defense Service Medal and the Selected Marine Corps Reserve Medal."
Melaku is still under the custody of the U.S. Park Police.