Almost 90 children needed medical assistance after an apparent outbreak of food poisoning at the Tavatui recreation camp in the Sverdlovsk region, the regional emergencies department said Friday.
"The number of children with health complaints has risen to 88," the department said in a statement carried by Interfax.
According to the statement, 25 children fell ill and were taken home by their parents, 37 were staying at a medical facility in the town of Novouralsk near the stricken camp, 21 children were sent to Yekaterinburg, and five remained at the camp's infirmary.
A quarantine has been put in place at the camp to prevent the potential spread of infection.
Novouralsk's municipal administration provided buses and ambulances to transport 210 children who had not been affected by the illness from the camp to their homes.
Earlier reports said all the infected children were in good or satisfactory condition.
Sverdlovsk region Governor Yevgeny Kuivashev has ordered an investigation into the causes of the mass poisoning. Preliminary reports suggest that food poisoning could have caused the outbreak.
Local health officials say they have everything they need to assist the children, while regional authorities will check all other children's camps in the region to prevent similar incidents from occurring.