Bread maker Hofuku, which has admitted one of its products is probably responsible for causing more than 1,000 children in Hamamatsu, Shizuoka Prefecture, to suffer food poisoning, has started recalling its products from retailers, including supermarkets in Yamanashi, Shizuoka, Aichi and Okayama prefectures.

According to the Hamamatsu Municipal Government, the bread the local company produced Monday and delivered to schools Tuesday morning is likely to have been tainted with the norovirus.

The municipal authorities’ inspection Thursday night detected the virus from a rest room slipper at the company’s plant, according to city and board of education officials.

The city ordered Hofuku to suspend operations.

Twenty-three workers were involved in the bread slicing and packaging process at the factory Monday when the norovirus-tainted bread was made.