Washington, May 7 - An apparently inattentive driver who began following the motorcade carrying President Obama's daughters near the White House set off alarms and forced security authorities to lock down the presidential mansion for an hour as a precaution.
Around 2.40 p.m. Tuesday, a dark automobile entered the White House security checkpoint at the intersection of 17th Street and Pennsylvania Avenue and moved some yards into the zone barred to traffic in front of the residence.
According to the Secret Service, which is in charge of presidential security, the suspicious vehicle tried to enter the prohibited zone following the motorcade carrying Sasha and Malia Obama, the president's daughters.
Agents immediately stopped the car, arrested the male driver and thoroughly searched the vehicle to rule out any threat from explosives.
The alert, which mobilised the entire White House security detail, was lifted approximately an hour later.
Later, authorities announced that the driver was carrying an employment pass for the Internal Revenue Service, the building for which is located near the White House but which is normally not accessible by that route.
Despite the calm that generally prevails in front of the White House, where hundreds of tourists stop each day to admire the mansion and where a discrete police and Secret Service presence monitors the vicinity, incidents of this kind are not unusual.
The most serious such situation occurred six months ago when a 34-year-old woman, who was driving with her 14-month daughter, crashed her vehicle into one of the White House access barriers and was pursued by police to the nearby Capitol, where officers shot her dead.
The woman, who had psychological problems, was shot five times despite being unarmed and apparently having no intention to attack the president.
The majority of cases such as the one Tuesday, however, end without serious consequences.