(Beaverton, OR) -- Beaverton Police are warning about a group of thieves that targets customers of fitness centers. While people are working out, they steal credit cards and go to nearby retail stores and buy big ticket items, including gold bars jewelry. In one case, they bought over 18-thousand-dollar's worth of gold bars from a Costco. They have been operating in at least five western states. They're described as Eastern European males. Anyone with information should contact Beaverton Police.