The first Soviet official explanation of the accident was by means of presentations from leading Soviet scientists and engineers to a large number of representatives from IAEA member states and other international organisations at the first Post-Accident Review Meeting, held at the IAEA in Vienna between 25 and 29 August 1986. This explanation effectively placed the blame on the power plant operators. The IAEA INSAG-1 report followed shortly afterwards in September 1986, and on the whole also supported this view, based also on the information provided in discussions with the Soviet experts at the Vienna review meeting. In this view, the catastrophic accident was caused by gross violations of operating rules and regulations. For instance; "During preparation and testing of the turbine generator under run-down conditions using the auxiliary load, personnel disconnected a series of technical protection systems and breached the most important operational safety provisions for conducting a technical exercise."