Security has been stepped up in Kenya after al-Qaida reportedly claimed responsibility for last month's attacks on Israeli targets on the Kenyan coast.
Kenya's deputy police commissioner, William Langat, says the whole country is on high alert against further terrorist attacks.
Thirteen people, 10 Kenyans and three Israelis, were killed when three suicide bombers attacked the Israeli-owned Paradise Hotel on the Kenyan coast, on November 28. At about the same time, missiles were fired at an Israeli airliner leaving Mombasa International Airport, but missed their target.
The al-Qaida terrorist network has now reportedly claimed responsibility for the attacks, and threatens to target more U.S. and Israeli targets.
Kenya is considered vulnerable because it is a popular tourist destination for Israelis, and a firm military ally of the United States.
Since the Mombasa attacks, the Kenya navy is intensively patrolling the coastal waters. Police have erected roadblocks to check incoming vehicles at hotels, restaurants and other places frequented by foreigners.
Security has also been strengthened at diplomatic missions in Nairobi. The British and U.S. embassies were closed on Thursday and Friday because of potential terrorist threats.
Kenyan police are holding 13 people for questioning in connection with the terrorist attacks. Kenyan and Israeli investigators are jointly examining the missiles that were fired at the airliner, and later recovered in a field.
It was the second major terrorist attack in Kenya in recent years. In 1998, more than 200 people died when the American Embassy in Nairobi was blown up. Al-Qaida is suspected to have masterminded that attack.