SAN'A, Yemen (AP) - Western embassies in Yemen locked up Sunday after fresh threats from al-Qaida, and the White House expressed alarm at the terror group's expanded reach in the poor Arab nation where an offshoot apparently ordered the Christmas Day plot against a U.S. airliner.
President Barack Obama's top counterterrorism adviser, John Brennan, cited "indications al-Qaida is planning to carry out an attack against a target" in the capital, possibly the embassy, and estimated the group had several hundred members in Yemen. Security reasons led Britain to act, too; it was not known when the embassies would reopen.
The U.S. is worried about the spread of terrorism in Yemen, a U.S. ally and aid recipient, Brennan said, but doesn't consider the country a second front with Afghanistan and Pakistan in the fight against terrorism.
As to whether U.S. troops might be sent to Yemen, Brennan replied: "We're not talking about that at this point at all." He pledged to provide the Yemeni government with "the wherewithal" to take down al-Qaida.
Britain and the United States are assisting a counterterrorism police unit in Yemen as fears grow about the increasing threat of international terrorism originating from the country.
The Obama administration claims that the suspect in the plot against the Detroit-bound plane was trained and armed by the al-Qaida affiliate in Yemen. Brennan blamed a series of what he called lapses and human errors in U.S. intelligence and security defenses for allowing a Nigerian man to board the plane with explosives. He tried to detonate them as the aircraft approached Detroit on Dec. 25.
The Transportation Security Administration announced Sunday that, starting Monday, passengers flying into the United States from Nigeria, Yemen and other "countries of interest" will be subject to enhanced screening techniques, such as body scans and pat-downs.
Yemen is a poor, decentralized and predominantly Muslim country on the Arabian Peninsula. It is the ancestral homeland of al-Qaida leader Osama bin Laden, and the site of the 2000 bombing of the USS Cole, which killed 17 U.S. sailors. A 2008 attack on the U.S. Embassy killed one American.
Given the active threat from al-Qaida, "we're not going to take any chances," Brennan said from Washington during appearances on four Sunday talk shows.
Sen. Joe Lieberman identified three instances in which terrorists or sympathizers penetrated or evaded U.S defenses last year - shootings at a military recruiting station and an Army base and the airline attack - and said all three were linked to Yemen.
"We've got to focus there pre-emptively, and I'm confident we will," said Lieberman, an independent from Connecticut.
The Yemeni government, which issued no official comment on the embassy closures, is friendly to the West but the population is often mistrustful of Western motives and influence. Yemen has pledged to clamp down on militancy, but government control is weak outside the capital and the country has a history of freeing some alleged militants and tolerating others.
The Obama administration is growing more vocal about both the threat and the San'a government's limitations. Brennan said Westerners are at risk in Yemen until the government gets a better handle on extremism.
The U.S. will look case by case at whether to repatriate the remaining approximately 90 Yemeni detainees held at the Guantanamo Bay prison camp, Brennan said.
Seven of 42 Guantanamo detainees freed by the Obama administration were returned to Yemen, Brennan said, but doubts about the country's ability to police further freed detainees is a major obstacle to Obama's plan to shut down the facility. Brennan reaffirmed the U.S. administration's support for the closure, but said that with regard to the Yemeni detainees, nothing would be done to put U.S. citizens at risk.
U.S. officials say terrorists are seeking new places to operate, including Yemen, Somalia and Southeast Asia, in part because of pressure on their previous sanctuaries in Afghanistan and Pakistan.
Some U.S. officials have said privately that Yemen's location at the heart of the Arab world, its history of tribal control, poverty, corruption and an ongoing civil war could make it the crucible of a future war. Brennan said the Obama administration is trying to head off the threat now.
Gen. David Petraeus, the U.S. general who oversees the wars in Iraq and Afghanistan, made a surprise visit to Yemen over the weekend. Following meetings with President Ali Abdullah Saleh, Petraeus announced that Washington this year will more than double the $67 million in counterterrorism aid that it provided Yemen in 2009.
The U.S. and Britain are funding a counterterrorism police unit in Yemen, and Britain plans to host an international conference Jan. 28 to come up with a strategy to counter radicalization in Yemen.
The United States has increased military cooperation with Yemen, with intelligence and other help to back two Yemeni air and ground assaults on al-Qaida hide-outs last month that were reported to have killed more than 60 people. Yemeni authorities said more than 30 suspected militants were among the dead.
The U.S. has stepped up intelligence, surveillance and training aid to Yemeni forces during the past year, and provided some firepower, a senior U.S. defense official has said. Some of that assistance may be through the expanded use of unmanned drones, and the U.S. is providing funding to Yemen for helicopters and other equipment. Officials, however, say there are no U.S. ground forces or fighter aircraft in Yemen.
On Thursday, the U.S. Embassy sent a notice to Americans in Yemen urging them to be vigilant about security.
Yemeni security officials said over the weekend that the country had deployed several hundred extra troops to Marib and Jouf, two mountainous eastern provinces that are al-Qaida's main strongholds in the country and where airliner suspect Umar Farouk Abdulmutallab may have visited last year.
U.S. intelligence agencies did not miss a telltale sign that that could have prevented the 23-year-old Nigerian man's alleged attempt to blow up the airliner, Brennan said.
"There is no smoking gun," Brennan said. "There was no single piece of intelligence that said, 'this guy is going to get on a plane.'"
Brennan is leading a White House review of the incident. Obama ordered a thorough look at the shortcomings that permitted the plot, which failed not because of U.S. actions but because the would-be attacker was unable to ignite an explosive device. The president has summoned homeland security officials to meet with him in the White House Situation Room on Tuesday.
Brennan cited "a number of streams of information" - the suspect's name was known to intelligence officials, his father had passed along his concern about the son's increasing radicalization - and "little snippets" from intelligence channels. "But there was nothing that brought it all together."
"In this one instance, the system didn't work. There were some human errors. There were some lapses. We need to strengthen it."
Brennan didn't say whether anyone is in line to be fired because of the oversights. He stood by Homeland Security Secretary Janet Napolitano, although he acknowledged she has "taken some hits" for saying that the airline security system had worked. It didn't, and she clarified her remarks to show she meant that the system worked only after the attack was foiled, Brennan said.