PARIS (Reuters) - Twenty-seven Chinese tourists were assaulted on Tuesday by half a dozen men as they boarded a bus that was to take them to Paris's Charles de Gaulle airport, a French police source said.

The assailants stole some pieces of luggage and injured two of the tourists, who were taken to hospital for treatment. "They sprayed the driver with tear gas and hit two tourists," the source said.

The value of the goods stolen could not immediately be established.

Attacks on Chinese, Korean and Japanese tourists are frequent in the French capital as robbers believe they carry large sums in cash and their suitcases are stuffed with luxury goods purchased in Paris.

In May, Paris Mayor Anne Hidalgo travelled to Beijing to reassure Chinese authorities that the world's most visited city had taken measures to beef up its security.

Tourist traffic in Paris has dropped significantly since bloody attacks by Islamist militants last November, leading to sharp declines in sales for luxury goods makers but also for the capital's retailers, hotels and restaurants.

Big luxury brands such as LVMH's Dior and Louis Vuitton and Richemont's Cartier have been hit hard by the drop in the number of free-spending Asian tourists in Paris as they make a significant proportion of their annual sales in the French capital.

(Reporting by Gerard Bon; Writing by Astrid Wendlandt; Editing by Tom Heneghan)