US fighter jets late Wednesday escorted a British Airways passenger plane to Washington's international airport where it was detained on the tarmac so its 247 passengers could be questioned by federal agents, The Washington Post said Thursday.
Federal Bureau of Investigation spokeswoman Debbie Wierman said some of the passengers "were folks that law enforcement officers were interested in speaking with." A Transportation Security Agency (TSA) spokeswoman said no specific incident on the plane prompted the investigation.
No arrests were made, and after five hours all passengers were allowed off the plane, which was kept at all time several hundred feet (scores of meters) from a terminal gate, the daily said.
While the passengers were being questioned by FBI and Transportation Security Agency (TSA) agents, the airliner and all the baggage on board were thoroughly inspected, a TSA spokesman told the daily.
British Airways flight 223, en route from London's Heathrow Airport was escorted to Dulles International Airport by several US fighter jets, a British Airways spokesman told the daily.
It landed at Dulles at 7:06 pm (0006 GMT Thursday). On Monday, the US government announced it would require foreign airlines to place armed security guards aboard flights into or out of the United States when it deemed it necessary.
The New York Times said Thursday terrorist concerns drove US authorities in the past week to impose extraordinary security measures on six incoming flights, including late Wednesday's flight 223, and to force a flight from Mexico to turn back because its passengers had not been properly screened.
The incident at Dulles came as a nation-wide terror alert clouded New Year celebrations across the country, with flight restrictions enforced over several major cities, including New York, Chicago and Las Vegas.
The US government raised its nation-wide security level on December 21 from yellow, denoting an "elevated" risk of attack, to orange, or "high" risk, amid concerns of an impending attack on US territory.
"We remain concerned about al Qaeda's desire to conduct attacks against commercial airlines within the United States," a Homeland Security spokesman said.