The Obama administration authorized a series of drone strikes in Yemen over the past 10 days as part of an effort to disrupt an al-Qaeda terrorism plot that has forced the closure of American embassies around the world, U.S. officials said.

The officials said the revived drone campaign — with five strikes in rapid succession — is directly related to intelligence indicating that al-Qaeda’s leader has urged the group’s Yemen affiliate to attack Western targets.

The strikes have ended a period in which U.S. drone activity in the Arabian Peninsula has been relatively rare, with a seven-week stretch with no strikes. The latest strike, in southern Yemen on Wednesday, killed seven alleged militants, the Associated Press reported. A strike on Tuesday reportedly killed four militants in the impoverished nation’s Marib province, a Yemeni security official said.

Although the BBC reported Wednesday that the terror plot had been disrupted,citing statements by Yemeni government officials, U.S. intelligence officials remain skeptical that the danger has passed. One intelligence official said the plot as described by the Yemenis — involving blowing up pipelines and taking over oil and gas facilities — may have been only one component of a broader plan to hit Western targets.

Officials said Tuesday there is no indication that senior al-Qaeda operatives in Yemen have been killed in the drone strikes.

“It’s too early to tell whether we’ve actually disrupted anything,” a senior U.S. official said, speaking on the condition of anonymity because of the sensitivity of the matter. The official described the renewed air assault as part of a coordinated response to intelligence that has alarmed counterterrorism officials but lacks specific details about what al-Qaeda may target or when.

“What the U.S. government is trying to do here is to buy time,” the official added.

The State Department underlined that approach on Tuesday, announcing that it had ordered the evacuation of much of the U.S. Embassy in the Yemeni capital of Sanaa and urged all Americans to leave the country immediately.

In a global travel alert, the State Department said that all non-emergency U.S. government personnel would be removed “due to the continued potential for terrorist attacks.” It described an “extremely high” security threat level in Yemen.

Yemen is the home base of al-Qaeda in the Arabian Peninsula, the branch of the terrorist group thought to be the most likely to attack U.S. or Western interests. The U.S. Embassy in Yemen was among 19 that were closed through Saturday, as were embassies in Yemen representing several European nations. The British Embassy said Tuesday that it had removed its staff.

The State Department’s decision drew a sharp rebuke from the Yemeni government, which said the evacuation “serves the interests of the extremists and undermines the exceptional cooperation between Yemen and the international alliance against terrorism.”

“Yemen has taken all necessary precautions to ensure the safety and security of foreign missions in the capital,” the Yemeni Embassy in Washington said in a statement.

State Department spokeswoman Jennifer Psaki took issue with Yemen’s assertion that the U.S. move rewards terrorists and said the decision to remove Americans from the country for safety reasons speaks for itself.

At the same time, jihadists took to Web forums to celebrate the closure of the embassies, with some boasting that doing so was a “nightmare” for the United States, according to the SITE Intelligence Group, a nonprofit organization that monitors the forums.

The burst of drone activity provides new insight into the Obama administration’s approach to counterterrorism operations. U.S. officials said the CIA and the U.S. Joint Special Operations Command, which operate parallel drone campaigns in Yemen, have refrained from launching missiles for several months in part because of more restrictive targeting guidelines imposed by President Obama this year. Those new rules, however, allow for strikes to resume in response to an elevated threat.

“They have been holding fire,” said a U.S. official with access to information about the al-Qaeda threat and the drone campaign. But intercepted communications between al-Qaeda leader Ayman al-Zawahiri, who is believed to be in Pakistan, and his counterpart in Yemen, Nasir al-Wuhayshi, have raised concern that the network is preparing an assault on Western targets.

“The chatter is coming from Yemen,” the official said. Embassies outside the region were closed not because they were specifically mentioned but because in Yemen and other countries, they would be prominent targets.

A few dozen U.S. Special Operations forces have been stationed in Yemen since last year to train Yemeni counterterrorism forces and to help pinpoint targets for airstrikes against al-Qaeda targets in the country. The U.S. military carries out drone strikes in Yemen from its base in Djibouti, while the CIA flies armed drones from a separate base in Saudi Arabia.

The CIA and the U.S. military have carried out 16 drone strikes in Yemen this year, according to the New America Foundation, which monitors the drone campaign. Last year, a record 54 strikes occurred.

The Pentagon said it will keep an undisclosed number of military personnel in Yemen to support the U.S. Embassy “and monitor the security situation.” U.S. military officials did not specify how many Americans were flown out of Yemen or where they were taken.

Residents in the capital reported seeing and hearing a low-flying aircraft that many believed to be a U.S. drone or some form of surveillance plane.

Raghavan reported from Nairobi. Craig Whitlock at Fort Bragg, N.C., Julie Tate in Washington and Ali Almujahed in Sanaa, Yemen, contributed to this report.