A total of 28 people have suffered food poisoning after dining at MOS Burger restaurants in Tokyo and other locations in Japan, the operator and other sources said.
Twelve of the 28 were infected with the same O-121 strain of E. coli bacteria, the Ministry of Health, Labor and Welfare said Friday.
Those affected had dined at 19 restaurants in eight prefectures in eastern and central Japan between Aug. 10 and 23, the operator, MOS Food Services Inc., said.
One of the restaurants in Ueda, Nagano Prefecture, suspended operations for three days through last Wednesday following an order from a local public health office, the company said.
"It is highly likely that (the illness) was caused by foodstuffs supplied (to the restaurants) by the headquarters of the chain," it said.