An Investigation of Non-Random Component in Extensive Air Showers Energy above 0.1 PeV at Sea Level

We have been searched for consecutive events in extensive air showers from mid of summer 1989. Four series of 15 EAS's coming within 10 minutes are found in 210k events of observed EAS. Each lump of the events has extremely small number of expected frequencies O(10^<-4> to 10^<-3>) in short data acquisition period. For these four series of events for total 210k events we got a significant level of 2.4×10^<-2>, which is not very strong evidence deviating from the Poisson distribution of random events. We began to observe EAS with adding Im2 plastic scintillation detectors to the old system from mid of June 1991. Also we report a preliminary result obtained from 46k events data briefly.