By the CNN Wire Staff
Investigators were studying an explosive device Tuesday that they say terrorists in Yemen crafted to slip past airport metal detectors and onto an airplane bound for the United States.
The device is more sophisticated than previous efforts and represents a disconcerting advance in al Qaeda bomb-making techniques, officials said Tuesday. However they said it never posed an immediate danger to air travel.
But lawmakers said the device may not be the only one made, and House Intelligence Committee chairman Mike Rogers said what he called the premature release of information surrounding the device could complicate an ongoing effort to seal the long-term threat.
"If something bad happens because it was leaked too early, that's a catastrophe and it's also a crime," Rogers told CNN.
On Monday, officials said U.S. and other intelligence agencies had seized the explosive device, which they said was similar to ones previously used by al Qaeda in the Arabian Peninsula. Western officials describe that group as al Qaeda's most dangerous affiliate, the FBI said.
Rep. Peter King, chairman of the House Homeland Security committee, and a senior administration official both said the intended user of the bomb is no longer a threat.
CNN national security contributor Frances Townsend said that doesn't necessarily mean the would-be bomber is dead.
"He's in custody wherever that device was seized," she said.
U.S. intelligence agents recently thwarted the plot after receiving a tip from Saudi Arabia, a source familiar with the operation said.
King said activities surrounding the bomb plot are linked to Sunday's death of Fahd al Quso, a senior operative of al Qaeda in the Arabian Peninsula who was killed in a U.S. drone strike in Yemen.
"I was told by the White House they are connected; they're part of the same operation," he said.
He did not provide further details.
Citing the ongoing operation, officials have declined to provide many specifics about the makeup of the device, which is undergoing analysis by FBI experts, according to U.S. officials.
A senior U.S. official said it had similarities to the underwear bomb that failed to explode aboard a Detroit-bound airliner on Christmas 2009. But the official also said the device showed differences highlighting al Qaeda's efforts to overcome measures designed to thwart its terrorist ambitions.
Rogers said the bomb's construction was more advanced than previous models.
"This is a device that was more sophisticated, had some failsafes built into it, and it was something that concerns us because it tells us that they brought some very capable people together to build something," he said.
U.S. officials were confident they were in control of the situation leading up to the seizure of the improvised explosive device, or IED, John Brennan, the chief White House counterterrorism adviser, said on ABC's "Good Morning America."
That's language that suggests the U.S. or its allies had someone working inside the organization, Townsend said.
Brennan said that officials believe redundant security systems surrounding air transportation would have prevented any successful attack, but that analysts are poring over the device to see if adjustments should be made.
"Now 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," although they continue to monitor efforts to carry out such attacks.
The threat was foiled around the same time as the anniversary of the raid that killed Osama bin Laden, although a second U.S. counterterrorism official said the attempted attack was not timed to coincide with the death of the al Qaeda leader.
President Barack Obama was told about the plot in April, and the attempt "underscores the necessity of remaining vigilant against terrorism here and abroad," the White House said.
Al Qaeda in the Arabian Peninsula, the organization believed to be behind the plot, has been responsible for two of the most audacious attempts to target the United States in recent years: the attempted Christmas 2009 bombing and a 2010 attempt to load bombs made from printer cartridges onto cargo planes headed for Chicago. In both cases, U.S. authorities believe the bombs were built by Ibrahim al-Asiri. Both devices contained a main charge of PETN, a white powdery explosive that conventional "single beam" X-ray machines are rarely able to detect.
In 2009, al-Asiri fitted out his brother, Abdullah al-Asiri, with a PETN-based underwear bomb to kill Prince Mohammed bin Nayef, a top Saudi security official. The device killed his brother instantly but failed to kill its target.