On "Face the Nation" this morning, Rep. Peter King, R-N.Y., the ranking member of the House Homeland Security Committee, said that AQAP was also involved in the Underwear Bomber plot that was foiled in Detroit last Christmas, and was tied to Major Nidal Malik Hasan, the sole suspect in last year's Fort Hood Shooting.
King said Yemen represents the "new major battleground in the war against terrorism."
Also on the program, White House Counterterrorism Adviser John Brennan said that the early investigation into the explosive packages that were intercepted on their way from Yemen to addresses in the United States appear to have been designed to detonate in flight.
Brennan said AQAP represents a very serious threat.
"Al Qaeda on the Arabian Peninsula is a group we've been following for quite some time," he told host Bob Schieffer. "We believe they were responsible for the Underwear Bomber last Christmas. They were responsible for trying to assassinate the prince of Saudi Arabia."
He said there were strong similarities among the three cases which suggest that they are the work of the same individual or individuals.
"They've been very vocal in their threats against U.S. interests, and determined to try to carry out attacks here in the homeland," Brennan said. "They present a very serious threat. This plot, I think, is part of that threat. We need to find these individuals who are responsible and bring them to justice as soon as possible."
Brennan said arrests made so far in Yemen have been of women who are believed to be responsible for bringing the packages to the UPS and FedEx shipping offices in Sana'a.
"The sophistication of this device requires a number of people who are involved," Brennan said. "We are concerned about individuals in Yemen who have very proficient bomb-making capabilities who are very dangerous. I do think there are a number of individuals who are responsible for putting this plot together."
Brennan credited information passed on to the U.S. from Saudi Arabia with enabling the devices to be located and neutralized.
"We're not presuming that we have found all the devices that are out there," he said. "I think prudence tells us to make sure that we're doing everything possible to screen cargo coming from that part of the world even more rigorously than we have."
Yesterday the U.S. announced an embargo on all shipments originating from Yemen.
Brennan said the Yemeni government recognizes the threat posed by AQAP.
"They've grown in strength. The Yemenis have been fighting courageously against the al Qaeda terrorists that are in their country. It is a very active operational franchise of al Qaeda. And so this I think just underscores the need for us to work even more closely with the Yemeni counterparts and to be as aggressive as possible in bringing these individuals to justice, so that they cannot harm innocents - whether they be in Yemen, the Arabian peninsula, or anywhere in the world."
King, a frequent critic of the Obama administration, admitted to having had differences with Brennan in the past, but said today, "Let me make it clear: On this particular matter I think the administration has handled it perfectly.
"They received the intelligence, shared it with their allies, did what had to be done. The FBI, the TSA especially, they did what they had to do. They shared it with local police like the NYPD here in New York. Everything was done right. They continue to do it right. I give them full credit."
More on Terror Packages:
Officials: Investigators Nearly Missed 1 Bomb
Mail Bomb Found in Dubai Was on Passenger Planes
Yemen Arrests Woman for Sending Mail Bombs
U.K. Official: Device Could Have Exploded
Investigators Searching for More Mail Bombs
Security Gaps Plague Cargo Shipping
Explosives Found on Planes Amid U.S. Terror Probe
PETN Explosive a Favorite of Terrorists
More on Yemen and al Qaeda in the Arabian Peninsula:
Yemen: The Next Front Line Against al Qaeda
Yemen Eyed as Source of Suspicious Packages
C.I.A. Drones May Target Yemen Terrorists
Concern Over Yemen Terror
CIA: Al Qaeda in Yemen Now Biggest Threat