Yemen's current president, Abdo Rabby Mansour Hadi, met with U.S. President Barack Obama at the White House on Thursday, where both leaders cited strong counterterrorism cooperation. Earlier this week, Yemen's military reported a U.S. drone strike killed six alleged al-Qaida militants in the group's southern strongholds.
As recently as June, the group's commander, Qasim al-Rimi, released an Arabic-language video urging attacks on U.S. targets and praising the ethnic Chechen brothers accused of carrying out the Boston Marathon bombings. "Making these bombs has become in everyone's ... reach," he said, according to the English subtitles on the video, reposted by private U.S. intelligence firm the IntelCenter.
"The blinking red intelligence appears to be pointing toward an Al-Qaida in the Arabian Peninsula plot," said Seth Jones, counterterror expert at the Rand Corp., referring to the branch of al-Qaida known as AQAP.
Britain also took action Friday in Yemen, announcing it would close its embassy there on Sunday and Monday as a precaution.
Britain, which closely coordinates on intelligence matters with Washington, stopped short of releasing a similar region-wide alert but added that some embassy staff in Yemen had been withdrawn "due to security concerns." British embassies and consulates elsewhere in the Middle East were to remain open.
Rep. Ed Royce, R-Calif., the House Foreign Affairs Committee chairman, said the embassy threat was linked to al-Qaida and concerned the Middle East and Central Asia.
"In this instance, we can take a step to better protect our personnel and, out of an abundance of caution, we should," Royce said. He declined to say if the National Security Agency's much-debated surveillance program helped reveal the threat.
The New York Times reported Friday night that American officials said the U.S. had intercepted electronic communications among senior operatives of al-Qaida.
Rep. C.A. Dutch Ruppersberger of Maryland, the top Democrat on the House Intelligence panel, also supported the department's decision to go public with its concerns.
"The most important thing we have to do is protect American lives," he said, describing the threat as "not the regular chitchat" picked up from would-be militants on the Internet or elsewhere.
The State Department issued another warning a year ago about potential violence connected to the Sept. 11 anniversary. Dozens of American installations were besieged by protests over reports of an anti-Islam video made by an American resident, and in Benghazi, Libya, the U.S. ambassador and three other Americans were killed when militants assaulted a diplomatic post.
The administration no longer says Benghazi was related to the demonstrations. But the attack continues to be a flashpoint of contention with Republicans in Congress who say Obama, former Secretary of State Hillary Rodham Clinton and others in the government misled the country about the nature of the attack after failing to provide adequate diplomatic protection.