Metro kicked off tighter security controls Tuesday, beginning randomized searches of riders’ bags at two stations during the morning commute. The first screenings, typically running well under a minute each, lasted for an hour at the Green Line’s College Park station and Braddock Road stop on the Yellow/Blue lines in Alexandria.

No explosives were found, and no terrorist suspects were arrested, according to spokeswoman Cathy Asato. “It went off as intended,” she said.