  Models where relativistic jets from merger or accretion induced collapse in
compact binary systems produce cosmological gamma ray bursts (GRBs) also
predict that GRBs are accompanied by delayed emission of high energy photons,
TeV neutrinos, X-rays, optical photons and radio waves. Their emission
mechanisms are similar to those responsible for their emissions by blazars
during gamma ray flares. The recently observed afterglow of GRB 970228 in
X-rays and optical photons is well accounted by such models. In particular, the
predicted power-law spectrum, time delay which is inversely proportional to
frequency and a power-law decay with time which is energy independent, are all
in excellent agreement with the observations.
