British Airways scrubbed one of three daily flights from London to the Washington area Thursday, the latest in a series of cancellations of international flights bound for the United States.

"The British government directed British Airways to cancel flight 223," said British Airways spokesman John Lamphill. "We can only assume that is due to security reasons. We have no other explanation."

Wednesday, another British Airways fight was detained several hours upon arrival at Washington's Dulles Airport while U.S. authorities questioned a number of passengers and conducted extra baggage screening. All passengers were eventually allowed to disembark.

FBI spokeswoman Debbie Wierman said authorities acted on "routine interest" rather than a specific threat or allegation.

"There were names listed on the manifest of the plane that matched [the names of] persons that U.S. law enforcement officials were interested in interviewing. It was routine interest on our part, and, when it was all said and done, we had no concerns or worries," she said.

But not everyone sees the stepped-up security effort as benign. One passenger from the delayed British Airways flight vented his displeasure. "This was detention without due process, as far as I am concerned. I am an American citizen and I expect to be treated as such in my own country," he said.

Last week, Air France canceled a half-dozen flights between Paris and Los Angeles. Wednesday, an AeroMexico flight bound for the United States was also scrubbed after U.S. officials raised security concerns with their Mexican counterparts.

The Associated Press quotes a spokesman for Mexico's government as complaining that U.S. officials did not share specific information about what provoked their concerns.