The US has warned that a terrorist attack could be "imminent" in the Kenyan city of Mombasa.
The US Embassy in Nairobi said yesterday that it had received "information of an imminent threat of a terrorist attack" in Mombasa, which lies on Kenya's south-east coast.
All US government employees have been told to leave Mombasa, while none will be allowed to travel there until July 1.
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The warning comes shortly after police in the port city seized chemical substances that they suspect were to be used to make explosives, the East African Standard reported. Two Iranians were arrested in Nairobi on suspicion of planning bomb attacks.
"We are ahead of the criminals," the newspaper quoted Kenya's acting head of civil service, Francis Kimemia, as saying.
Kenyan police commissioner Mathew Iteere also assured that authorities were "working around the clock to guarantee security," according to the BBC.
Mombasa and other Kenyan cities have been hit by a series of grenade attacks ever since Kenya sent troops into neighboring Somalia last year to fight Al Shabaab rebels, Reuters said.
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In May, one person was killed and five more injured when explosives were thrown into a Mombasa nightclub.
According to the Standard, Kimemia said the Kenyan authorities were working with US intelligence agencies to thwart other terrorist plots.
The US Embassy has issued a total of four travel warnings since last October, when Kenyan troops entered Somalia.