More than 900 people, including 622 children, are suffering from acute stomach infection and dysentery in hospitals in southern Russia after drinking contaminated dairy products.
The bad milk, cream and yoghurt was apparently produced at a factory in the town of Kropotkin in the southern Krasnodar region, where two employees of the plant have been diagnosed with dysentery.
Production at the factory was halted and all produce recalled after Krasnodar's regional prosecutor opened a criminal inquiry into the food poisoning.
Russia's chief medical officer, Mr Gennady Onischenko, criticised the factory's managers, saying they were making no effort to establish the cause of the illnesses.
The number of people suffering food poisoning has risen daily since the scare erupted on Wednesday.
Hygiene is considered generally good at Russian food producers but there have been some serious food poisoning scares.
The last case was in January last year, when 58 people, including 21 children, were rushed to hospital in central Russia after food poisoning from eating cakes made at a local shop.
AFP