By EILEEN SULLIVAN and LOLITA C. BALDOR

Associated Press Writers

WASHINGTON — Al-Qaida in the Arabian Peninsula today claimed responsibility for the attack on a U.S. airliner bound for Detroit on Christmas Day, saying it was retaliation for a U.S. operation against the group in Yemen.

Federal authorities met today to reassess the U.S. system of terror watchlists to determine how to avoid the type of lapse that allowed a man with explosives to board the flight in Amsterdam even though he was flagged as a possible terrorist.

In a statement posted on the Internet, al-Qaida in the Arabian Peninsula said 23-year-old Nigerian Umar Farouk Abdulmutallab coordinated with members of the group, an alliance of militants based in Saudi Arabia and Yemen.

Yemeni forces, helped by U.S. intelligence, carried out two airstrikes against al-Qaida operatives in the country this month. The second one was a day before Abdulmutallab attempted to bring down a Northwest Airlines flight as it prepared to land in Detroit.

The group said Abdulmutallab used explosives manufactured by al-Qaida members.

“He managed to penetrate all devices and modern advanced technology and security checkpoints in international airports bravely without fear of death,” the group said in the statement, “relying on God and defying the large myth of American and international intelligence, and exposing how fragile they are, bringing their nose to the ground, and making them regret all what they spent on security technology.”

The Obama administration has ordered investigations into how travelers are placed on watch lists and how passengers are screened, as critics and administration officials questioned how Abdulmutallab was allowed to board the flight. A senior U.S. intelligence official said authorities were reviewing the procedures that govern the lists, which could include how someone is placed on or moved between the various databases.

“Why wasn’t he flagged at a higher screening level?” Homeland Security Secretary Janet Napolitano said on ABC’s “Good Morning America.” “How did he get an explosive substance on to the plane? All of those are serious questions that we are now looking at.”

Passengers have faced stiffer boarding measures since Friday. Authorities warned travelers to expect extra delays returning home from holidays.

The intelligence official said the review will look at what adjustments could be made to avoid the type of gap that allowed Abdulmutallab to fly into Detroit even though Britain had refused to grant him a student visa in May. The official spoke on condition of anonymity to discuss the internal review.

Congress is already starting to weigh in. Sen. Joe Lieberman, I-Conn., said Monday that the Senate Homeland Security and Governmental Affairs Committee would hold hearings on the incident in January. Lieberman is chairman of the committee.

The White House press office, traveling with President Barack Obama in Hawaii, said Monday that the president would make a statement from the Kaneoho Marine Base in the midafternoon.

Abdulmutallab is accused of trying to detonate an explosive device hidden on his body as the plane approached Detroit on a flight from Amsterdam last Friday. Law enforcement officials say he tucked below his waist a small bag holding a potentially deadly concoction of liquid and powder explosive materials. The device burst into flames without exploding, according to authorities, and Abdulmutallab was subdued by passengers. The plane landed safely.

His name was one of about 550,000 in the Terrorist Identities Datamart Environment database, known as TIDE, which is maintained by the U.S. National Counterterrorism Center. Inclusion in that database does not trigger mandatory additional airport screening.

Napolitano conceded Monday that the aviation security system failed, backtracking from a statement Sunday in which she said the airline security system worked. She said her words had been taken out of context.

“Our system did not work in this instance,” she said Monday on NBC’s “Today” show. “No one is happy or satisfied with that. An extensive review is under way.”

Harold Demuren, the head of the Nigerian Civil Aviation Authority, said Abdulmutallab paid cash on Dec. 16 for the $2,831 round-trip ticket from Lagos, Nigeria, to Detroit via Amsterdam. He said Abdulmutallab’s ticket came from a KLM office in Accra, Ghana.

Demuren said Abdulmutallab checked into his flight with only a small carry-on bag.

Officials said he came to the attention of U.S. intelligence last month when his father, Alhaji Umar Mutallab, a prominent Nigerian banker, reported to the American Embassy in Nigeria about his son’s increasingly extremist religious views.

In a statement released Monday, Abdulmutallab’s family in Nigeria said that his father reached out to Nigerian security agencies two months ago. The statement says the father then approached foreign security agencies for “their assistance to find and return him home.”

Abdulmutallab had been placed in a U.S. database of people suspected of terrorist ties in November, but officials say there was not enough information about his activities to place him on a watch list that could have kept him from flying.

In Britain, Abdulmutallab was placed on a standard watch list of people whose visa applications were rejected, but he was not flagged as a potential terror suspect, British officials said Monday.

Abdulmutallab, who graduated from a London university last year, had his subsequent visa application denied in May 2009. British officials said the school on his application form was not a government-approved institution.