It was preceded by a foreshock almost as strong as the main quake.The foreshock occurred at 02:33 CEST (00:33 UTC), rated Mw5.7, and the second – the main shock – occurred at 11:40 CEST (09:40 UTC), rated Mw 6.0.The mainshock was assigned X (Extreme) and foreshock VIII (Severe) on the Mercalli intensity scale.[2] There were several thousands of foreshocks and aftershocks from May 1997 to April 1998, more than thirty of which had a magnitude more than 3.5.Only shocks (both foreshocks and aftershocks) with magnitude 5.0 or higher are listed.