Ammon News - AFP - The White House was briefly put on lockdown Tuesday after a car trailed an official motorcade that was reportedly carrying the daughters of US President Barack Obama.

The Secret Service, which is in charge of the president's security, said the vehicle followed the motorcade past a security barrier about 200 meters (650 feet) from the White House.

The driver, 55, was arrested and has been charged with unlawful entry, said Secret Service spokesman Edwin Donovan.

The vehicle "was immediately stopped by Uniformed Division officers," and subsequently investigated, Donovan said.

There was no official word on who was in the motorcade, but CNN, citing a source, said it was Obama's daughters Sasha and Malia, on their way home from school.

Reporters working in the White House were not allowed to leave the building for an hour in the afternoon until the lockdown was lifted.