WASHINGTON – The Pentagon’s intelligence branch has issued a terrorism alert to all U.S. interests in Kenya and raised the threat level there to “high,” a defense official said Friday.

The warning, issued Thursday by the Defense Intelligence Agency, is based on specific information about a threat against a specific target, the official said, speaking only on condition of anonymity.

Details of the warning, including the target and the nature of the threat, are classified secret, the official said.

The official would not say whether the target was the U.S. Embassy in Nairobi.

There are four terrorism warning levels; “high” is the highest of the four.

Kenya and other countries in the Horn of Africa have been a focus of U.S. counterterrorism efforts for many months. A special U.S. military task force has been operating in the Horn of Africa since late last year.

On May 27 the U.S. Embassy in Nairobi said it was reviewing its security against a heightened terrorist threat.

“The move is a precaution … based on the heightened security situation in Nairobi and Kenya over the past weeks,” the embassy said in a statement sent to U.S. citizens in the country.

Both the United States and Britain, along with other European countries, have warned a number of times of possible terrorist attacks in eastern Africa, specifically in Kenya.

Britain on May 15 suspended British Airways flights between Nairobi and London because of a specific threat to British airlines in Kenya.

U.S. officials and Western diplomats have said that intercepted communications among al-Qaida operatives in eastern Africa and other unspecified intelligence indicate terrorists may be plotting an attack on embassies or the residences of foreign officials in Nairobi.

There have been several terrorist attacks in Kenya in the past five years.