A U.S. Marine reservist was taken into custody in Arlington National Cemetery near the Pentagon early today after he was found to be carrying in his backpack materials initially deemed "very concerning." The FBI said later the materials were non-explosive.

Update at 5:13 p.m. ET: The FBI said the items, which have not been identified officially, were non-explosive but were undergoing further testing at the laboratory in Quantico, the AP reports.

Bomb-sniffing dogs and FBI agents wearing haz-mat suits searched a brick townhouse in Alexandria, Va., and removed items. Nothing suspicious was found in his car, authorities said.

The FBI said the suspect, 22-year-old Lance Cpl. Yonathan Melaku, is a naturalized citizen who was born in Ethiopia. He joined the Marine Corps Reserves in September 2007, is listed as a motor vehicle operator with the 4th Combat Engineer Battalion, headquartered in Baltimore, and has not been deployed overseas. He has received the National Defense Service Medal and the Selected Marine Corps Reserve Medal.

The Washington Post is reporting that Melaku was arrested early May 26 after more than 25 cars in Leesburg, Va., were vandalized. AP says he was charged with four counts of grand larceny.

By Douglas Stanglin

USA TODAY

Update at 12:18 p.m. ET: CBS News investigative producer Pat Milon, quoting unnamed sources, reports that the person who was detained has been identified as Lance Cpl. Yonathan Melaku, a member of the U.S. Marine Corps Reserve.

Update at 10:55 a.m. ET: The Associated Press quotes a law enforcement official, speaking on the condition of anonymity, as saying officials found what appeared to be a small quantity of ammonium nitrate in the suspect's backpack, but there was nothing that would have enabled an explosion. The official, the AP reports, says tests are being done to determine the exact concentration.

Update at 9:52 a.m. ET: U.S. Park Police detained a man early today who was found in Arlington National Cemetery near the Pentagon with a backpack containing suspicious materials.

FBI Agent Brenda Heck says the man, whose identity was not released, remains in custody. She says that despite earlier reports, there was only one individual involved in the incident.

Heck would not divulge the material found in bags in the suspect's backpack but says it was found to be "inert."

She would not comment on reports from ABC News that ammonia nitrate, spent 9mm shells and a pro-al-Qaeda note were among the items found.

Sgt.David Schlosser of the Park Service says the suspect was discovered in the cemetery around 1:30 a.m., which is against the law, and fled when approached by police from Fort Myers, which adjoins the cemetery.

Schlosser says the suspect was initially uncooperative but eventually led them to his car, which was parked near the Pentagon. Schlosser says nothing suspicious was found in the vehicle.

Update at 8:49 a.m. ET: ABC News, quoting unidentified sources, says the man had a backpack that contained what officials say is ammonium nitrate and spent 9mm shells as well as written material that contained statements including: "al qaeda taliban rules." ABC reports that the man "appears to be a U.S. citizen of Ethiopian ethnicity."

Update at 8:40 a.m. ET: David Schlosser of the U.S. Park Police says he is not sure at this point whether any devices have been found in connection with a suspicious car discovered near the Pentagon.

Schlosser confirms that one person was taken into custody early today in Arlington Cemetery, which is closed during overnight hours. He says the person was "uncooperative" and that led authorities to look at the vehicle parked near the Pentagon. He calls it a "suspicious-type situation."

He says that parts of the cemetery and nearby Iwo Jima Memorial were closed and that experts will conduct "sweeps" of the area.



Schlosser says he has no information on any controlled detonation of any suspicious device but noted that it was early in the investigation. He says he does not know the name or identity of the suspect.

Update at 8:19 a.m. ET: CBS News reports that the Department of Homeland Security is holding a person suspected of planting suspicious devices around the Pentagon, Arlington National Cemetery and the Iwo Jima Memorial.

Update at 8:13 a.m. ET: WUSA-TV reports that authorities have conducted a "controlled detonation" of a "suspicious device" found in the vehicle to render it harmless.

Original posting: NBC4-TV says the car was stopped around 5:50 a.m. today and police found a "suspicious device" inside the vehicle.

Pentagon police spokesman Chris Layman says one or two other people may be involved. Layman did not elaborate.

The car was located in bushes near the north parking lot of the Pentagon.

WUSA reports that authorities plan a "controlled detonation" to render the package harmless.