  In this paper we consider the properties of the 10 confirmed by the LIGO
Collaboration gravitational wave signals from the black hole mergers. We want
to explain non-observation of electromagnetic counterpart and higher then
expected merging rates of these events, assuming the existence of their sources
in the hidden mirror universe. Mirror matter, which interacts with our world
only through gravity, is a candidate of dark matter and its density can exceed
ordinary matter density five times. Since mirror world is considered to be
colder, star formation there started earlier and mirror black holes had more
time to pick up the mass and to create more binary systems within the LIGO
reachable zone. In total, we estimate factor of 15 amplification of black holes
merging rate in mirror world with respect to our world, which is consistent
with the LIGO observations.
