  We find that Gamma-ray bursts (GRBs) at the 3B catalog are correlated (at
95\% confidence level) with Abell clusters. This is the first known correlation
of GRBs with any other astronomical population. It confirms the cosmological
origin of GRBs. Comparison of the rich clusters auto-correlation with the
cross-correlation found here suggests that \sim 26 \pm 15\% of an accurate
(\delta<2.3 deg.) position GRBs sub-sample members are located within 600
\hmpc.
