On one side of the argument, Transportation Safety Administration screeners and law enforcement might more easily identify any similar devices made as part of the same plot, the official said.

But officials were reluctant to do so out of concern that the photographs would be leaked to the news media and that the would-be bombers would learn what law enforcement knows -- and might not know -- about the bomb's workings.

John Brennan, the chief White House counterterrorism adviser, who told ABC's "Good Morning America" on Tuesday that officials believe redundant security systems would have prevented any airline bombing attempt from succeeding, but analysts were studying the device to see whether security procedures should be adjusted.

"We're trying to make sure that we take the measures that we need to prevent any other type of IED, similarly constructed, from getting through security procedures," Brennan said.

A Department of Homeland Security spokesman said authorities have "no specific, credible information regarding an active terrorist plot against the U.S. at this time."

But another U.S. official told CNN, "We are not ready to say the threat stream is over. We believe external plotting continues."