Shares of Buffalo Wild Wings fell more than 7 percent on Wednesday as health officials reported they were investigating the cause of a gastrointestinal illness that struck diners at one of the company's restaurants in Kansas.
The illness, which caused vomiting and diarrhea, affected at least 10 diners who visited Buffalo Wild Wings' grill and bar in Overland Park, Kansas last week, the Kansas City Star reported.
Buffalo Wild Wings closed the restaurant on Saturday and called in a third-party vendor to clean it after diners reported feeling ill.
"Although there is no conclusive link to our restaurant being the source of the illness, we voluntarily took these actions out of an abundance of caution," a spokesman for the company said in a statement to CNBC.
"The restaurant re-opened Sunday following consultation with the health department."
Health officials who inspected the Overland Park restaurant over the weekend found 17 code violations, including liquor bottles that contained small, dead insects, and an employee wiping his nose, then resuming work without washing his hands or changing gloves, the Star reported.
Officials are continuing to look into the source of the illness.
"We are working with the Johnson County Department of Health and Environment, the City of Overland Park and the Kansas Department of Agriculture to investigate these illnesses," Sara Belfry, communications director for the Kansas Department of Health and Environment, said in a statement to CNBC.
"The exact cause and source of the illness is unknown at this time and is pending laboratory results."
— CNBC's Jeff Daniels contributed to this report.