Prosecutors have opened an investigation into an unexplained outbreak of chemical poisoning in a southern Russian region, where 33 people have been hospitalized over the past week, emergency response officials said Friday.
It was unclear what caused the poisoning, said the Emergency Situations Ministry department in the Kabardino-Balkariya region, some 1,900 kilometers (1,150 miles) south of Moscow. More than 130 people sought medical aid beginning April 15.
Among the 33 people hospitalized were 11 children.
Victims in the Tersky district of Kabardino-Balkariya complained of symptoms that included shortness of breath and nausea, according to hospital patients interviewed on Russian television. Three settlements were affected by the alleged poisoning.