Fears of an Al-Qaeda terror strike prompted the United States to issue a worldwide travel alert and order its embassies across the Islamic world temporarily closed.
Germany and Britain, meanwhile, announced that their embassies in the Arab and Muslim country of Yemen would be closed on Sunday and Monday for security reasons.
The US State Department warning, issued on Friday, warned of unspecified plans by the Al-Qaeda network to launch an attack against US interests in the Middle East or North Africa this month. Joint Chiefs of Staff chairman General Martin Dempsey told ABC News that the threats were directed at Western interests, and were "more specific" than previous threats.
While an exact target was unknown, "the intent seems clear. The intent is to attack Western, not just US, interests", Gen Dempsey said in an interview.
As a precaution, the State Department said it was closing at least 22 US embassies or consulates on Monday, a work day in many Islamic countries.
The German Foreign Ministry referred to the risk of "terrorist attacks in certain isolated parts of Yemen but also in the capital Sanaa".
The Britain's Foreign Office said the embassy was closing due to increased security concerns in the final days of the fasting month. US President Barack Obama ordered his national security team to "take all appropriate steps to protect the American people", a White House official said. The alert warned of "the potential for terrorists to attack public transportation systems and other tourist infrastructure".