Reuters  

WASHINGTON – As the Secret Service widened its security perimeter around the White House, Vice President Dick Cheney was moved to the Camp David presidential retreat to ensure that America’s two senior officials were not in the same place, officials said.  

The step was taken Thursday amid concern about the possibility of new threats two days after hijacked commercial jetliners rammed into the Pentagon and the World Trade Center in New York.  

President George W. Bush remained at the White House. But Mr. Cheney, a former defense secretary, who would ascend to the presidency if Mr. Bush were to die or become incapacitated, was evacuated to Camp David in the nearby Catoctin Mountains of Maryland as a precaution, according to the White House spokesman, Ari Fleischer.  

Mr. Fleischer said that the White House from now on would keep secret all information about the movements of Mr. Bush and Mr. Cheney.  

“It was a purely precautionary measure,” said a spokeswoman for Mr. Cheney, Juleanna Glover Weiss. She was asked if the vice president, who has had four heart attacks since 1978, was in good health. “He’s fine,” she replied.  

The Secret Service, which is responsible for the safety of the president, said Thursday it had expanded its security perimeter around the White House, further restricting pedestrian access and traffic nearby. A Secret Service spokesman, Marc Connolly, said traffic was being closed off for one block in each direction beyond the normal perimeter.  

Ronald Reagan National Airport, across the Potomac River from Washington, remained closed because of its proximity to key federal buildings.  

The Capitol was evacuated for 45 minutes Thursday after a telephoned bomb threat was received and sniffer dogs reacted to a package in a Senate office. Examination established that the package was harmless.  

The evacuation interrupted talks by lawmakers on a bipartisan resolution to give the president approval to order military strikes.