The U.K. Foreign Office did not provide many details of the new threat but indicated it was "specific" and could target Westerners, including aid workers, especially in the breakaway Somaliland region.
"We are now aware of a specific threat to Westerners in Somaliland and urge any British nationals who remain there against our advice to leave immediately," the Foreign Office said in a written statement.
The advisory warned of the threat of kidnapping "motivated by criminality or terrorism" and an overall wobbly security situation in the region.
The Foreign Office last week issued a similar advisory for British nationals in the Libyan city of Benghazi, the BBC said.
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