Hospitalized during February 3-7 students of Blagoveshensk agricultural secondary school drank unboiled tap water. This was informed by press-service of Far East regional administration of Russian Emergency Ministry. 17 students stay in isolation hospital with symptoms of poisoning at present moment. Their state of health is estimated as satisfactory. All patients have lived on different floors of student hostel and had no common foodstuff. First isolated instances of illness were registered on February 3 but patients didn`t address for medical assistance. The infection will be diagnosed within several days. Experts of territorial administration of Russian Consumer`s Inspection over Amur oblast and Amur territorial center of catastrophe medicine establish the cause of poisoning.