(CNN) -- Citing recent attacks, the United States on Wednesday announced that it has suspended public services at its embassy in Sanaa, Yemen.
"Due to recent attacks against Western interests in Yemen, we have temporarily suspended operations of our Embassy in Sana'a to the public," State Department spokeswoman Jen Psaki said in a statement. "We continue to evaluate the security situation every day, and we will reopen the embassy to the public once it is deemed appropriate."
She described the move as a "precautionary step."
The temporary suspension of operations is due to a reemergence of a threat from several weeks ago that the United States thought it had disrupted, according to a U.S. official with specific understanding of the current situation.
A credible threat to the U.S. Embassy emerged around March, the official said, in the same time frame that a video appeared showing some 100 al Qaeda operatives in Yemen, including several who had broken out of jail the month before.
The United States thought that threat had been disrupted by a number of Yemeni actions, including, but not directly related to a series of U.S. drone strikes and Yemeni military operations in early April.
But in recent days, the threat stream has reemerged, the official said. It is currently assessed to be credible and somewhat specific in terms of the embassy being the target, according to the source.
The United States is still attempting to corroborate the threat and determine whether there is a specific time and date, as well as any other specific locations.
A second U.S. official said the suspension of the embassy activity was based on credible information about threats to Western interests. The senior official was not sure whether the threat was embassy-specific. There have been no evacuations of the embassy.
The U.S. intelligence community has struggled in recent months to track al Qaeda in Yemen via electronic intercepts because the group has changed its communications, following disclosures last year of U.S. eavesdropping methods.
Still, the United States is using electronic tracking, satellite imagery and operatives on the ground to try to determine what may be planned.
The United Kingdom, meanwhile, advised against travel to Yemen and urged all British nationals to leave the country.
"There is a high threat from terrorism throughout Yemen and specific methods of attack are evolving and increasing in sophistication," the Foreign and Commonwealth Office said in a statement.
It continued: "Al-Qaida in the Arabian Peninsula (AQAP) has previously targeted western interests and there could be a threat to commercial sites, transport infrastructure, diplomatic missions and any place where westerners gather."
CNN's Elise Labott contributed to this report.