Britons are being advised to stay away from Kenyan coastal areas within around 90 miles of the Somali border after a second armed gang attack in a month.
The Foreign Office issued its warning after a French woman was kidnapped early on Saturday from a beach resort in the Lamu archipelago, northern Kenya, by 10 heavily armed Somali militants.
Security forces have tracked down and surrounded the pirate boat believed to be carrying the French hostage, identified as Marie Dedieu by the Kenyan government.
On September 11, Briton David Tebbutt, 58, was killed and his wife Judith, 56, was abducted by armed gunmen from a resort near the popular tourist town of Lamu.
In a statement, the FCO said: "We advise against all but essential travel to coastal areas within 150km of the Somali border, following two attacks by armed gangs in small boats against beach resorts in the Lamu area on 11 September and 1 October 2011.
"This advice will be kept under review. Both attacks were on beach-front properties, with two Westerners kidnapped and one murdered.
"Beach-front accommodation in that area and boats off the coast are vulnerable."
The Tebbutts, from Bishop's Stortford, Hertfordshire, were the only guests at the Kiwayu Safari Village, 25 miles from the Kenya-Somalia border.
The FCO said its travel advice is "under constant review in the light of the situation on the ground".
"Travel advice is based on objective assessments of the risk to British nationals, whose safety is our main concern," said the statement.
