Frank and Ann Miller of Hannibal, Mo., found out in the hardest possible way that a vacation villa in the Caribbean can be unsafe. Last winter, the couple rented a posh house for a month in the intimate beachside resort of Rendezvous Bay on the island of Anguilla. One morning in January they woke to find two armed and masked bandits in their bedroom. The intruders fled, but not before shooting the Millers, seriously wounding Ann. No arrests have been made.

An isolated incident in the paradisiacal islands? Yes and no. Travelers to Anguilla (population 13,000), the northernmost island in the Caribbean's Leeward chain, reported no threats with guns in 2004, two in 2005 and one this year, according to the Anguilla police.

By accounts published in the Caribbean news media and locals' blogs, however, break-ins at small hotels or vacation rentals are occurring more frequently on some Caribbean outposts and in parts of Bermuda and the Bahamas.

While they rarely give statistics, the Trinidad Guardian, Bermuda's Royal Gazette and other papers have covered the incidents thoroughly, documenting an increased pattern of armed robberies, burglaries and sometimes assaults. The kinds of properties many travelers seek in order to escape big-city dangers -- romantic and isolated, with little or no security -- are particularly vulnerable.

No overall regional statistics are available on burglaries or vacation home thefts affecting tourists in the Caribbean. However, the most recent U.S. State Department consular information sheets -- which give up-to-date safety information on countries around the globe -- cite break-ins in the past year in St. Lucia, Trinidad and Tobago, Anguilla, St. Kitts and Nevis, and the Dutch islands of Aruba, Bonaire and St. Maarten.

This year's listings on St. Lucia and St. Kitts and Nevis refer to break-ins for the first time. The reports have begun recommending that visitors lock up their valuables in safes in hotels and other properties on almost all Caribbean islands, Bermuda and the Bahamas, and in particular on islands where break-ins are a problem.

Until recently, the biggest worry facing most tourists in the Caribbean was petty crime: aggressive soliciting, muggings and purse snatchings. Many of the incidents took place near cruise ship ports, popular beaches or other tourist areas.

But in the past two years, according to accounts by travelers and in the Caribbean press, a rising number of infractions have occurred in vacation accommodations that had little or no prior record of incidents, or in areas where crime had rarely tracked on the radar. In most of the cases, the intruders broke into locked quarters and took cameras, cell phones, cash, lap tops, and passports and other travel documents. In some cases, they raped or killed victims.

"We're not saying don't go to these islands," said a State Department spokesman who asked not to be quoted by name, in keeping with department policy. "But don't expect because you're in a tropical, relaxed area that you're out of a danger zone. Take the same precautions that you would in other places."

Most tourism authorities and property owners also emphasized the low crime rate in the islands compared with resorts in the United States or other places. Linda Smith, owner of Luxury Jamaica Villas by Linda Smith in Cabin John, Md., said there have been no robberies or other infractions in any of her rentals. "For me, crime has been a non-issue," she said.

One alarming trend in the region, according to accounts in the Caribbean media, is nighttime break-ins when guests are in their rooms. One case involved the Missouri couple shot during the robbery attempt in Anguilla. Three others took place this year in isolated boutique hotels on St. Lucia, according to the latest State Department information sheet on the island, updated this fall to include information about the attacks.

One of the cases involved the U.S. couple robbed and attacked at St. Lucia's Mago Estate. The two were so shaken by the ordeal that they created a Web site, www.stluciatravel.org, detailing their experience and two similar cases on St. Lucia. When the intruders left, their account says, the couple left the room and found the estate's two security guards sleeping. "We want you to be aware of the risks involved in traveling to St. Lucia," they write on their site. "And we want to prevent this from happening to you."