Authorities searched a Delta Air Lines jet at Hartsfield Atlanta International Airport on Friday after a bomb threat. Nothing was found, but more than 100 passengers were forced to take other flights.

None of the passengers had yet boarded Delta Flight 350, a 767 that was scheduled to take off for Boston at 8:10 a.m. The flight was canceled, and the jet was moved away from the concourse during the search.

Deputy Transportation Secretary Michael Jackson, on an unrelated visit to the airport to discuss security, confirmed that a bomb threat had been called in.

"This was a contained issue related to one specific plane," he said. Airport and Delta officials "handled it perfectly appropriately."

Delta spokeswoman Peggy Estes said law enforcement officers had completed their search of the plane and issued an all-clear after finding nothing suspicious.

Delta arranged to get the 102 scheduled passengers to Boston, Estes said. No other flights were delayed, she said. It was not immediately clear whether authorities interviewed passengers.

Atlanta Police Sgt. Frank Roberts told the Atlanta Journal-Constitution that bomb-sniffing dogs had searched the plane's luggage.

"This is becoming routine," he was quoted as saying on the newspaper's Web site.

The security threat happened just before Jackson was to tour Hartsfield, one of 15 airports that the new Transportation Security Administration will study over the next six weeks.

The agency, which takes over airline security Feb. 17, is studying the airports to develop new security procedures for the nation's 429 commercial airports.