One man is in custody this morning and major Beltway roads shut down after police stopped a “suspicious vehicle” near the Pentagon:

Authorities say one person has been taken into custody in connection with an investigation into a suspicious vehicle near the Pentagon.

Pentagon police spokesman Chris Layman says the person was taken into custody early Friday and that one or two other people may be involved. Layman says the car is in bushes near the Pentagon’s north parking lot.

It’s not a case of a stolen vehicle or normal predatory behavior, either. Otherwise, the police wouldn’t be planning to conduct a “controlled explosion” of the car:

Channel 9 is reporting authorities are planning to do a controlled explosion of the suspicious vehicle.

The case apparently began last night when police arrested a “suspicious man,” and after interrogating him, determined that it was important to locate his vehicle.  Initial reports state that police may be looking for two other men, but initial reports in these cases are notoriously unreliable.  So far, the bomb squad has not conducted a controlled explosion but are still inspecting the vehicle.

We’ll update when more becomes available.

Update: The Washington Post now reports that the police arrested the man in Arlington Cemetery last night:

Roads around the Pentagon were shut down this morning after authorities took a “suspicious man” into custody overnight in Arlington Cemetery, said Sgt. David Schlosser, a spokesman for the U.S. Park Police.

The man was found in the cemetery after it closed and Schlosser said authorities decided it was “important” to locate his vehicle following an interview with him. Arlington County police found the car off of Washington Boulevard near the Pentagon early this morning, Schlosser said.

Update II: According to the New York Post, police found what they probably expected:

Authorities found al Qaeda-related statements, a backpack containing ammonium nitrate, and spent 9mm shells Friday after stopping a suspicious vehicle close to the Pentagon and arresting a man, ABC’s “Good Morning America” reported.

Pentagon Police arrested one person Friday and closed several roads around the US Department of Defense headquarters after officers stopped a suspicious vehicle and discovered a backpack believed to contain ammonium nitrate, FOX News Channel reported.

The suspect fits the profile, too:

A source told FOX News Channel that the backpack was found outside of the vehicle, and that the arrested man was a naturalized US citizen who came to the US from Ethiopia.

We’ll see whether these get confirmed in later reports, but it’s clear why police acted to seal off the area.  What’s not clear is why the suspect would have lurked overnight in Arlington National Cemetery and aroused suspicion.

Update III: According to WTOP’s Twitter feed, “No suspicious device in backpack. inert materials in backpack, according to FBI. man acted alone.”

Update IV: The Washington Post’s updated story says nothing suspicious was found in the car:

Authorities have found “nothing suspicious” in an abandoned vehicle that prompted officials to close a number of roads around the Pentagon on Friday morning or on a man detained overnight in connection with the incident, an FBI official said.