A U.S. Marine reservist was detained early Friday after being found acting "suspiciously" in Arlington National Cemetery before dawn, setting off a security scare that closed commuter routes around the Pentagon for a few hours to snarl morning rush-hour traffic, authorities said.

Information from the detained man, identified as 22-year-old Yonathan Melaku, led authorities to a car parked in bushes on the side of a road near the Pentagon and prompted explosives experts to examine the red 2011 Nissan, according to an FBI statement.

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 is 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.