The chief medical officer of the Volgograd region in southern Russia, where 120 pupils were hospitalized over the weekend with symptoms of acute gastroenteritis, said Monday that the children might have contracted salmonella.
Alexander Zlepko said, "The symptoms and the results of preliminary analysis cause me to believe that the children contracted salmonella, although we will get the final results Tuesday."
A total of 120 students and a teacher at a secondary school in Volgograd were hospitalized with symptoms of acute gastroenteritis.
A hospital official said all of the patients had felt bad after lunch in a school dining hall but were now in "satisfactory" condition.
Local prosecutors are investigating the incident.