The U.S. Secret Service cleared Pennsylvania Avenue in front of the White House on Monday and closed one of its gates after a bomb-sniffing dog alerted them to a car in a nearby garage.
Pedestrians were told by the Secret Service and U.S. Park Police that the area was closed.
White House staff and journalists were not allowed through the northwest gate at the White House but some personnel were allowed to use the east gate.
The closure of Pennsylvania Avenue, which is open only to pedestrian traffic and official vehicles on the White House block, came after a bomb-sniffing dog alerted officers to a car parked in the garage of the nearby New Executive Office Building, a Secret Service spokesman said.
District of Columbia police were examining the car.
Earlier, authorities had said the closure was prompted by an unattended package.
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