SAN'A, Yemen — Western embassies in Yemen locked up Sunday after fresh threats from al-Qaida, and the White House expressed alarm at the terrorist group's expanded reach in the poor Arab nation.
President 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.
Yemeni officials on Sunday dismissed the threat posed by al-Qaida as "exaggerated" and downplayed the possibility of cooperating closely with the United States.
Analysts said the statements by Yemen's foreign minister, chief of national security and Interior reflected domestic political concerns about making President Ali Adbullah Saleh appear weak and beholden to the West as he faces numerous political challenges.
The U.S. is worried about the spread of terrorism in Yemen, a U.S. ally and aid recipient, Brennan said. An al-Qaida offshoot there apparently ordered the Christmas Day plot against a U.S. airliner, but the U.S. doesn't consider Yemen a second front with Afghanistan and Pakistan in the fight against terrorism, he said.
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 the Nigerian man to board the plane with explosives. He tried to detonate them as the aircraft approached Detroit.
U.S. intelligence agencies did not miss a telltale sign that that could have prevented the attempt, Brennan said.
"There is no smoking gun," he said. "There was no single piece of intelligence that said, 'this guy is going to get on a plane.' "
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.
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 Saleh, Petraeus announced that Washington this year will more than double the $67 million in counterterrorism aid that it provided Yemen in 2009.