Arlington: A man carrying a backpack containing what authorities said were suspicious materials briefly fled police Friday before he was detained in the middle of the night near the Pentagon.
The man, who is in his 20s, was discovered inside Arlington National Cemetery after 1 a.m., several hours after the cemetery had closed. The man, who has not been identified, was initially uncooperative. Authorities believe he acted alone.
The man was in custody but has not been charged with anything.
The man had an unknown quantity of a substance that appeared to be ammonium nitrate in his bag, according to a law enforcement official speaking on the condition of anonymity. Ammonium nitrate is a chemical compound that is widely used in fertilizers and can be used in explosives with the correct concentration.
Nothing else was found on the man that could have triggered an explosion, said the official, who spoke on the condition of anonymity because they were not authorized to release the information. Tests were being done to determine the substance and the exact concentration, the official said.
During the course of the investigation, officers searched the man`s nearby car, a red 2011 Nissan that was parked in the bushes near a Pentagon parking lot, but found nothing suspicious inside, said Brenda Heck, special agent in charge of the counterterrorism unit of the FBI`s Washington field office.
She would not disclose the materials inside the backpack, but said it contained no explosives.
In another incident earlier this week, a motorist found with a gun and what appeared to be a suspicious package near the Pentagon was taken into custody.