RIYADH, Saudi Arabia - The United States will close its missions in Saudi Arabia on Saturday for an undetermined period because of "credible" information that terrorists are about to carry out attacks, the U.S. Embassy said Friday.
The United States also warned that Taliban insurgents in Afghanstan may attempt to kidnap American journalists working in that country.
The U.S. Embassy in the Saudi capital, Riyadh, said Americans in the kingdom should be "vigilant when in any area that is perceived to be American or Western."
The embassy said in a warden message on its Web site that the missions in Riyadh, Jiddah and Dhahran would close to assess their "security posture."
They will then advise the American community when the review is completed and when the missions plan to resume normal operations.
The embassy said it had received "credible information that terrorists in Saudi Arabia have moved from the planning to operational phase of planned attacks in the kingdom."
On Monday, Saudi police uncovered a cell believed linked to al-Qaida network in the holy city of Mecca. Police believe the cell had planned to carry out attacks during Ramadan.
The alert came a day after two suspected militants, believed to be members of the Mecca cell, blew themselves up in the holy city to avoid arrest. A third suspect was killed in a shootout with security forces in Riyadh, the Saudi capital.
The Saudi government launched a nationwide security crackdown following the May 12 attacks on Western compounds in Riyadh. About 600 suspects believed linked to al-Qaida have been arrested since the May attacks, which killed 35 people, including the nine attackers.
In Afghanistan, the U.S. Embassy in Kabul said it has "credible information that Taliban forces are actively searching for American journalists to take hostage for use as leverage for the release of Taliban currently under United States control."
In a statement released to journalists, it advised them "to increase their security posture."
The Taliban were ousted by a U.S.-led coalition almost two years ago. The U.S. military holds Taliban captives at Bagram Air Base, the coalition's headquarters north of Kabul, as well as at a detention facility on Guantanamo Naval Base, Cuba.
Fighters with links to the former regime have stepped up attacks in recent months, mostly in southern and eastern Afghanistan. On Oct. 30, Taliban insurgents abducted a Turkish road engineer, demanding the release of Taliban prisoners. Negotiations were continuing.