Armed robbers wearing women's wigs and clothing made off with diamond rings, gem-studded bracelets and other jewelry worth $108 million from a Harry Winston boutique in Paris, in one of the world's largest jewel heists. As Christmas shoppers strolled outside, the gunmen forced store employees to strip rings, necklaces and earrings from window displays and pull more out of safes, Isabelle Montagne, spokeswoman for the Paris prosecutor's office, said Friday. The brazen robbery early Thursday evening took place in the presence of security guards and security cameras in one of Paris' toniest shopping locales, just steps away from the tourist-filled Champs-Elysees. Besides Harry Winston, Nina Ricci, Gucci, Chanel and Dior are among the fashion houses with boutiques on the Avenue Montaigne. The robbers threatened the 15 employees with handguns and hit some on the head, according to a police official who cannot be identified under agency policy. The robbers spoke a foreign language at times and appeared to know employees' names, the official said. Montagne said there was only one client in the store at the time, and no one was injured and no weapons were fired. She called the incident "very well-organized," and said three of the four gunmen were dressed as women and wore wigs. Investigators seized the store's surveillance tapes and police said one group under suspicion was the so-called "Pink Panthers," a ring of jewel thieves mostly from the former Yugoslavia. The international police agency Interpol has blamed the group for jewel thefts in 19 countries in Europe, Asia and the Persian Gulf worth more than $150 million over the past 10 years. Paris' Harry Winston boutique was targeted in a similar heist last year, when three thieves made off with $28.4 million worth of jewels after forcing employees to open safes. They were never caught. French police called Thursday's robbery one of the world's costliest jewel thefts. Five years ago, robbers plundered 123 maximum-security vaults in Antwerp, Belgium, stealing $100 million worth of diamonds in what was then considered the biggest jewel theft. The Paris robbers chose one of the world's most glamorous targets: Harry Winston jewels have adorned Queen Elizabeth, Elizabeth Taylor, Madonna and numerous Hollywood celebrities. The jeweler is famous for its one-of-a-kind diamond-studded pendants, opulent chandelier earrings and colored diamonds in vivid shades of yellow, blue and pink. "We are cooperating with the authorities in their investigation. Our first concern is the well-being of our employees," New York-based Harry Winston said. Rhonda Barnat, a spokeswoman for the company, did not provide further details. The boutique was closed Friday, and three of its five display windows stood empty of their usual stunning jewelry. Vendors at the nearby Louis Vuitton and Max Mara boutiques said they did not notice anything unusual Thursday - until police sirens wailed. Harry Winston declared to insurers that the stolen goods were worth $108 million, the Paris prosecutor's office said. Geoff Field, CEO of the British Jewelers' Association, called it a "pretty sensational" robbery, but added: "There are well-known gangs around looking to target high-value diamonds." He stressed the stolen jewels would be difficult to sell "through any legitimate channels." "They will undoubtedly be certified," he said, adding: "There will be a record of their quality, their cut, their weight, their color, and they will be identifiable." Passers-by at the Harry Winston store wondered the same thing Friday. "How do you fence it? How do you get rid of it?" asked tourist Richard Conacher, a 39-year-old hotelier from Melbourne, Australia. "You'd have to think they were famous pieces." A half-century ago, company founder Harry Winston donated the Hope Diamond - the world's largest blue diamond and famed for the bad luck that it brought its owners - to the Smithsonian Institution. Thursday's robbery comes as a security monitoring group for the French jewelry industry has reported a 20 percent rise in armed robberies over last year, with 132 taking place through November.