(CNN) -- Somalia's pirates have long made the country's coastline a no-go area for sailors, but two brutal attacks on resorts in neighboring Kenya have sparked fears the militants may have dramatically altered their tactics.
In recent years, reports of ships large and small being hijacked in the Gulf of Aden and the Indian Ocean by Somali pirates have become commonplace, with dozens of seafarers and their vessels held captive, in some cases for months.
But when the world's navies descended on the region in an attempt to protect shipping, the pirates found their grip on the area challenged.
And rather than face off against the might of highly-trained personnel and warships from the U.S. and dozens of other countries, some appear to have begun looking for easier targets, switching their attention from ships off the coast to holidaymakers across the border.
The golden sands and crystal blue waters of Kenya's Lamu Archipelago are straight out of the pages of a glossy travel magazine, the stuff of wealthy holidaymakers' dreams.
Tiny, exclusive resorts nestle alongside deserted beaches from which tourists can spot turtles, whale sharks and dolphins. The toughest challenge most visitors face is deciding which hammock to settle in.
But this slice of paradise exists cheek by jowl with the war-torn, lawless border region of Somalia, and last month the two worlds collided, with deadly consequences.
On September 11, the idyllic calm of the luxurious destination was shattered, when armed bandits broke in to the beachfront cottage where Britons Judith and David Tebbutt, both in their 50s, were staying.
David Tebbutt was shot dead while trying to resist the attack. His wife was grabbed and spirited away onboard the pirates' speedboat. She is believed to have been taken into Somalia.
And on October 1, pirates made another cross-border raid, this time snatching a French woman in her 60s from the holiday home on Manda Island where she lived for part of the year.
Kenyan officials said Kenyan navy personnel pursued the attackers in their high-speed boat, engaging in a shootout, but the gang managed to cross the border back into Somalia.
In the wake of the most recent attack, Britain's Foreign Office changed its advice to tourists heading for Kenya, warning against "all but essential travel to coastal areas within 150km of the Kenya-Somalia border," and cautioning that beachfront accommodation in the region is particularly vulnerable.
The U.S. State Department urges U.S. citizens to avoid travel all to Somalia, and warns American visitors to Kenya of previous incidents in which Westerners have been kidnapped and smuggled into Somalia.
Kenya Police spokesman Eric Kiraithe said it was likely resorts close to the border were seen as "soft targets" -- despite the presence of police and security guards -- an attractive proposition given the clampdown on 'traditional' pirate attacks.
"They certainly must have seen it as a soft target," he told CNN. "We know in the sea the entire international community has come to there, and it has become increasingly difficult for them -- and these are people looking for easy money."
Security analyst Will Geddes said the pirates' apparent change of tack was a worrying one -- and not just for tourists, but for the authorities in Kenya and Somalia -- because it showed that the attackers felt they could not be stopped by the police.
"The fact that the pirates are feeling that they are suitably uncontrolled by any infrastructure of law enforcement that [impedes] them from carrying out actions into tourist resorts," was of particular concern, he told CNN.
Geddes said Kenyan authorities needed to take action -- quickly -- to protect tourists, and the country's valuable tourist industry.
"Some big questions will now need to be asked to the Kenyan government as to what security measures they can now install to reassure the international community and also tourists visiting their country that they will be safe."
CNN's David McKenzie contributed to this story.