The Pentagon's intelligence branch has issued a terrorism alert to all U.S. interests in Kenya.
A source with the Defense Intelligence Agency confirms that a terrorism alert has been issued for Kenya.
The source, who spoke on the condition of anonymity, says the warning is based on specific information about a threat against a specific target.
Details of the warning, including the target and the nature of the threat, are classified secret. The source says the warning level for Kenya is already set at "high." The source described the threat as being like a "tornado warning." The source says "we've seen the funnel cloud so we put out the warning."
U.S. officials say al-Qaida operatives are in the region and intercepted telephone communications indicate terrorists may be planning attacks on embassies or foreign residences. The State Department says the U.S. embassy in Nairobi will be closed at least until the middle of next week.
A spokesman says the embassy is closed to review security issues.
Kenya and other countries in the Horn of Africa have been the focus of counter-terrorism efforts for months. A special U.S. task force has been operating in the area since last year. Both the United States and Britain have warned a number of times of possible terrorist attacks in East Africa, especially Kenya.
Last month Britain suspended British Airways flights between Nairobi and London because of a specific threat to British airlines. There have been several terrorist attacks in the past five years.
In November of last year suicide bombers killed at least 14 people at an Israeli-owned resort in Mombassa. On the same day two heat-seeking missiles were fired at an Israeli plane leaving from Mombassa on its way to Tel Aviv. The missiles missed the plane and no one was hurt.
In 1998 terrorists from al-Qaida attacked the U.S. embassies in Nairobi and Dar Es-Salaam, Tanzania killing more than 220 people in both attacks.