London ( CNN ) -- One British citizen was killed and another one was kidnapped overnight at a resort near Kenya 's border with Somalia , Britain 's Foreign Office told CNN Sunday . The attack occurred at a beach resort north of Lamu , Kenya , the foreign office said . A maritime security source aware of the situation said the victims were a couple and the husband was killed . His wife has likely been taken by Islamic militants by boat toward Ras Kamboni in Somalia , the source told CNN . `` We are working to secure the safe and swift release of the British national who has been kidnapped and ask those involved to show compassion and release the individual immediately , '' the foreign office said in a statement . British officials did not release further details about the kidnapping case , but said they are working closely with Kenyan authorities . The office said it has amended its travel advice for Kenya in light of the attack . `` We continue to advise against all but essential travel to within 30 kilometers of Kenya 's border with Somalia . There have been previous attacks by Somali militia into Kenya , '' the advisory said . CNN 's David Wilkinson contributed to this report .
NEW : Kidnapped British woman may have been taken to Somalia . The BBC reports that the woman, who was kidnapped in Kenya last month, is now believed to be held by Al-Shabaab militants on a remote Somali island. The foreign office advises against travel near Kenya 's border with Somalia .