Nairobi - The US embassy in Kenya warned on Monday of a possible attack which is "in the last stages of planning" on Nairobi hotels and key government buildings and urged American citizens to be cautious.
"Timing of the attack is not known, however, the embassy has reason to believe that the potential attack is in the last stages of planning," the embassy said in a statement.
Kenya has been hit by several grenade attacks targeting bus stations and bars since it sent troops into southern Somalia in October to battle the al-Qaeda affiliated Shabaab insurgents it blames for cross-border attacks.
In the latest attack on 01 April, at least one person was killed and 18 others wounded when explosives went off in the coastal city of Mombasa and a nearby town.
The extremist rebels warned Nairobi of reprisal attacks, prompting security officials to ramp up surveillance, with guards at several buildings including shopping malls now screening visitors.
In 1998, the US embassy, then in central Nairobi, was bombed by al-Qaeda operatives who rammed its gate with an explosives-laden truck.
A total of 213 people, including 12 Americans and 34 local embassy staff, died in the 07 August 1998 bombing. The United States has since moved its embassy out of the city centre.