BANGOR – The procedure for checking baggage at Bangor International Airport has become a little more complicated.

A law went into effect Friday requiring airlines to check bags for explosives – either by machine, hand or bomb-sniffing dog, or by matching each piece of checked luggage to a passenger on board. As the travel day got into full swing, there were no reports of major problems, either nationally or at BIA.

“This is not an airport issue, but an airline issue,” said BIA regulations and compliance officer and airport security coordinator Frank Carr at a news conference Friday afternoon.

Carr said the airport primarily is concerned with ensuring airlines are in compliance with the regulations set forth by the Federal Aviation Administration.

Airlines at BIA have implemented a combination of physical searches of checked luggage and matching bags with passengers.

“If you board an aircraft and then get off the plane for any reason, the bags have to come with you,” Carr said, explaining what airlines are calling positive bag matches. “They can’t fly without you.”

In addition, luggage checked by passengers for standby flights won’t be loaded onto the plane unless the passenger leaves on the same flight.

Carr added there’s a chance the positive bag matches could cut back on lost luggage.

Although the increased security was expected to cause delays at the major airports, the new regulations didn’t upset the flow of airport activity in Bangor.

“It doesn’t seem to be presenting too many problems,” Carr said. “It may take a few more minutes, but not a huge amount of time.”

Delays varied at the three airports from where the Sept. 11 hijackers departed. Boston’s Logan International Airport was filled with long, slow lines, but the queues at Newark International Airport were moving smoothly. At Dulles International Airport near Washington, D.C., some seasoned travelers appeared confused and frustrated as they were directed to a line for checked baggage inspection.

At Philadelphia International Airport, the flow of passengers through baggage check-in lines appeared to be near normal. Lines at New York City’s La Guardia and John F. Kennedy International airports; Detroit; Baltimore; Oakland, Calif.; Las Vegas; Miami; Albuquerque, N.M.; Tampa, Fla.; Manchester, N.H.; Columbus, Ohio; Omaha, Neb.; Oklahoma City and Pittsburgh also appeared to be flowing well.

In Portland, where Mohamed Atta and a companion boarded a flight bound for Boston last Sept. 11, passengers seemed to take the changes in stride.

“It’s probably a good thing,” said Dan Stevens of Lewiston, en route to Charlotte, N.C. “Everything they can do to make it safer is better.”

Teresa Holden of Falmouth, waiting to fly to New York City, said she doubts the new rules will have much of an impact.

“I feel relatively safe anyway,” she said. “And this doesn’t make me feel any more or less safe.”

Eventually, BIA will have explosive trace detection systems installed in the airport for checked luggage. Distributed by the FAA, the detection systems already have been installed in some airports around the country, although Carr couldn’t say when BIA would be outfitted.

“[The systems] are being deployed by the FAA as fast as they can do it,” Carr said.

ETD systems have been in use for carry-on luggage for more than a year.

The Associated Press contributed to this report.