The Soviet Union first drew much suspicion of violating its obligations under the BWC after an unusual anthrax outbreak in 1979 in the Soviet city of Sverdlovsk resulted in the deaths of approximately 65 to 100 people. The Soviet authorities blamed the outbreak on the consumption of contaminated meat and for years denied any connection between the incident and biological weapons research. However, investigations concluded that the outbreak was caused by an accident at a nearby military microbiology facility, resulting in the escape of an aerosol of anthrax pathogen. Supporting this finding, Russian President Boris Yeltsin later admitted that "our military developments were the cause".