Petersburg has reported the reception of two suspicious letters. The press-service of the Petersburg Head Civil Defence and Emergencies Department told RIA Novosti on Wednesday that the Petroteknip company received a letter on Tuesday morning. When the company's secretary opened the letter white powder spilt out of it. Those employees who touched the envelop were immediately isolated. However, a rapid analysis by experts of the city's sanitary-epidemiological department proved the powder was not dangerous and that it was not necessary to keep those who touched the substance isolated. On Tuesday evening a city resident found powder in an envelope with bills which was not proved to be dangerous on a rapid analysis. In future the State Sanitary-Epidemiological Department will analyse any powder found in letters. Meanwhile, qualified bodies have already started investigating the reasons for the emergence of the suspicious envelopes.