NAIROBI, Kenya — The security bulletins warning of an impending assault by terrorists are rising in intensity as Kenya's capital increases security measures in hopes of preventing what would be the first massive attack here since the 1998 U.S. Embassy bombing.
The U.S. Embassy this week put out new rules prohibiting visitors from bringing electronics or laptop computers into the compound. Shopping malls are installing new security rules. And a new, high-end hotel has shuttered its underground parking garage.
Al-Shabab, Somalia's al-Qaida-linked militant group, has repeatedly promised to attack Kenya in retaliation for Kenyan forces moving into southern Somalia in October. The group's spokesman threatened to bring Nairobi's skyscrapers down, and though an attack of that magnitude appears unlikely, intelligence officials fear some attack is imminent.
One Western diplomat told The Associated Press that recent intelligence reports show that al-Shabab is trying to obtain security guard uniforms they can wear while carrying out an attack, a common tactic used by militants in Afghanistan. The diplomat spoke on condition he was not identified discussing sensitive intelligence matters.
One analyst said he is surprised large-scale attacks haven't happened already.
"I don't think it's going to be grenade attacks. It's going to be a massive truck bomb, simultaneous attacks. This is a signature of al-Shabab and al-Qaida," said Rashid Abdi, a former Somalia analyst with the International Crisis Group who is setting up an independent policy forum. "I think they want to make a huge statement."
Al-Shabab carried out simultaneous bombings in Kampala, Uganda last year as the World Cup final played on TV. Those attacks killed 76 people. Uganda contributes troops to the African Union force that is fighting al-Shabab.
Last weekend Britain's Foreign Office warned that terrorists may be "in the final stages of planning attacks," and Kenyan authorities said they had thwarted attempted attacks by al-Shabab over the holidays. A new al-Shabab video posted last week shows a militant named Ahmad Iman Ali urging Muslims in Kenya to wage jihad.
The U.S. Embassy this week set its new security rules. Guards have been issued new instructions to "stop and diligently screen" all vehicles with diplomatic plates on them, according to a security directive obtained by The Associated Press.
In 1998, a truck bomb that was parked outside the U.S. Embassy in downtown Nairobi killed more than 200 people. A simultaneous explosion detonated in Tanzania's capital. In total 224 people died, mostly Kenyans, but also including 12 Americans.
On Tuesday a text message circulated widely in Nairobi saying that the U.N. had issued a bomb threat alert for Tuesday night. Kenyan police held a news conference to deny that the text message was real. Police spokesman Eric Kiraithe said police are monitoring dozens people in Kenya who have been in contact with al-Shabab, and "10 among them are considered lethal."
Kiraithe also said there has been a spike of Westerners who sympathize with al-Shabab flying into Kenya with the intention crossing over to Somalia to fight for the group. In the last two weeks seven people from Western countries, including the U.S. and UK, have been arrested and deported after trying to make contact with al-Shabab, he said.
A former U.S. Army soldier was arraigned Monday on charges related to trying to join al-Shabab.
Kiraithe said Kenya has done its best to secure itself against terrorism and that no country in the world can claim to be completely secure against a terror attack.
But the atmosphere is still tense. Police are working double shifts in order to beef up their presence on Nairobi's streets, said one senior police officer who requested anonymity because he is not allowed to speak with media.
Abdi said he is puzzled that al-Shabab had not yet carried out an attack. That could be because its command corps has been degraded by fighting, or because the group is having second thoughts.
"Al-Shabab probably recognizes that Kenya is important logistically," he said. "It uses it as a conduit for funneling funds in and out of Somalia. It is a safe haven in many ways."
The U.S. Embassy reissued its security warning for U.S. citizens in Kenya late Monday. The warning says it has received information of potential threats directed at prominent Kenyan locations where foreigners congregate, such as malls and nightclubs.
One businessman at a shop selling high-end animal carvings said Tuesday he was discounting his goods because tourist numbers are down, in part because of the rash of security warnings. He said he did not fear a terror attack despite the fact his business was adjacent to Nairobi's Hilton Hotel, though he did refuse to give his name because he did not want to be confronted by security authorities.
Abdi said he believes Kenyans are much more vigilant than in the past.
"But all of this is new for Kenyans," he said. "I don't think the reality has probably sunk in, the threat that this country faces and what could happen if al-Shabab attacks."
Associated Press reporter Tom Odula contributed to this report.