It began after the Secret Service reported a car tried to follow a motorcade through the security checkpoint at 17th Street and Pennsylvania Avenue. The vehicle was stopped by uniformed Secret Service officers and the driver was placed under arrest.
The Secret Service says the driver who tried to follow the motorcade into the White House was a U.S. Treasury Department passholder. The motorcade was for the Obama daughters.
The passholder remains in custody.
The lockdown was lifted after about an hour.