Authorities from the Metropolitan Professional Inspection Agency said the local license holder of the KFC franchise, Tavan Bogd, was responsible for the 247 cases of diarrhoea, vomiting and fever reported this month.

Officials said they found serious violations in health standards and a failure in internal hygiene controls.

Lab tests detected bacteria in the drinking water and E coli in soda.

Yum! Brands, which oversees the franchise, said KFC Mongolia is cooperating with the government’s investigation.

“There is nothing more important to KFC than the health and safety of our customers,” the company said in an emailed statement. “We deeply regret the negative impact that many people have suffered.”

Tavan Bogd, which also holds rights to Yum’s Pizza Hut chain of restaurants in Mongolia, said the location linked to the illness was closed for further monitoring while the company works to retrain its staff.

All other locations are currently operating, said spokesman Zolbayar Batsukh.

Tavan Bogd Group launched its first KFC location in 2013, under its subsidiary Tavan Bogd Foods, and has since expanded to more than 10 locations in the capital city.