  A search for Gamma Ray Bursts in the GeV-TeV energy range has been performed
by INCA, an air shower array working at 5200 m of altitude at the Chacaltaya
Laboratory (Bolivia). The altitude of the detector and the use of the "single
particle technique" allows to lower the energy threshold up to few GeVs. No
significant signals are observed during the occurrence of 125 GRBs detected by
BATSE, and the obtained upper limits on the energy fluence in the interval
1-1000(100) GeV range from 3.2(8.6) 10^-5 to 2.6(7.0) 10^-2 erg/cm^2 depending
on the zenith angle of the events. These limits, thanks to the extreme altitude
of INCA, are the lowest ever obtained in the sub-TeV energy region by a ground
based esperiment.
