  In a recent paper, Romero et al. (1999) have presented the results of a
positional correlation analysis of the low-latitude unidentified gamma-ray
sources in the Third EGRET catalog with complete lists of galactic objects like
supernova remnants, early type stars with strong stellar winds, and OB
associations (considered as pulsar tracers). We have now carried out a study of
those 42 sources at |b|<10 deg for which no counterpart was found at all. A
variability analysis shows that this sample contains a population of sources
with high levels of variability at gamma-rays. The surface density of these
variable sources is 5 times higher than what is expected for unidentified AGNs
seen through the Galactic plane. We discuss the origin of this presumed
Galactic population of gamma-ray objects and the role that INTEGRAL could play
in their physical identification.
