  We report our observations on 4 AGNs viz, Mkn421, Mkn501, 1ES1426+428 and
ON231 belonging to a sub-class called blazars. The observations were carried
out using the Pachmarhi Array of Cherenkov Telescopes and span about 6 years
period from 2000 to 2005. We discuss our methods of analysis adopted to extract
the gamma ray signal from cosmic ray background. We present our results on the
emission of TeV gamma rays from these objects. Also, we report on the status of
the new high altitude experiment, a 7 telescope array at Hanle in the Himalayas
at an altitude of about 4200 m above mean sea level for detecting celestial
gamma rays.
