Updated

U.S. Embassies on Tuesday warned of possible terror attacks against two hotels in Kenya (search) and a housing compound for Westerners in Saudi Arabia (search). Kenyan police said they were investigating reports that terrorists had packed a truck with explosives for an imminent attack.

The embassy warnings focused on two nations that have seen a number of attacks by Usama bin Laden's Al Qaeda (search) network. Further heightening fears, two banks in the Kenyan capital were evacuated due to bomb threats that turned out to be unfounded.

A U.S. counterterrorism official, speaking on condition of anonymity, said there was no Al Qaeda connection that they were aware of. He had no information on who British authorities had apprehended.

Also Tuesday, British police arrested 14 people on suspicion of terrorism offenses in raids in London and other cities Tuesday. The suspects' names and nationalities were not released.

Four men were arrested in London, and four men and two women were arrested at two separate locations in the university city of Cambridge, police said. Four men also were arrested in Dudley and Walsall in central England.

Sussex Police, meanwhile, charged North African native Noureddinne Mouleff, 36, with conspiring to defraud banks of large sums of money, Sussex Police said. He and five others were arrested last under anti-terror laws. Police said investigations were ongoing related to the other five.

The U.S. State Department issued an advisory Tuesday warning of suspected plans for a terror attack aimed at American and Western interests in downtown Nairobi, particularly two hotels. "The timing of the threat is within the next several days," the statement said.

U.S. Embassy spokesman Peter Claussen said U.S. authorities received an anonymous tip on Monday detailing the threats. The information was passed on to Kenyan authorities.

United Nations security officials also advised employees against visiting the downtown area Tuesday or Wednesday.

Jonathan Koskei, the senior police official for Nairobi, said the U.S. Embassy alerted Kenyan authorities three days ago about intelligence reports that indicated terrorists had packed a truck with explosives and were planning to attack a hotel.

"We've been investigating these threats, but we cannot confirm the existence of this truck," he said. The Kenyan police deployed their main paramilitary unit to both hotels and the bank buildings.

In Tuesday's bomb scares, the Barclay's Bank building was evacuated for four hours, along with a second Barclay's branch office in downtown Nairobi. The South African embassy, in the same area as the banks, was closed Tuesday, but embassy personnel refused to comment.

Al Qaeda has twice struck Kenya. The old embassy was destroyed in 1998 by a car bomb, an attack that killed 219 people, including 12 Americans. Kenyan police reportedly uncovered a plot to destroy the new U.S. Embassy this past June.

In Riyadh, Saudi Arabia, terrorists had the Seder Village compound under "active surveillance," the Embassy spokeswoman in Saudi Arabia, Carol Kalin, told The Associated Press by phone from the Saudi capital. She said other housing complexes may also be targeted.

Kalin said the embassy had barred its American employees and dependents from visiting housing compounds in Riyadh between the hours of 6 p.m. and 6 a.m. "except for official business."

"The Embassy continues to be concerned about the current security situation in Saudi Arabia, particularly the housing compounds in the Riyadh areas," Kalin said.

Britain advised British nationals in Saudi Arabia to maintain a high level of vigilance, particularly in places frequented by foreigners such as hotels, restaurants and shopping malls. Britain has previously advised against all nonessential travel to the kingdom.

There are some 30,000 Americans living in Saudi Arabia. The U.S. Embassy was scheduled to resume work Wednesday following a weeklong closure for a Muslim feast.

Militants attacked three compounds for foreigners in Riyadh in May, detonating vehicle bombs that killed 35 people including the nine assailants. Another homicide attack killed 17 people in the capital on Nov. 8.