  The microquasar V404 Cygni underwent a series of outbursts in 2015, June
15-31, during which its flux in hard X-rays (20-40 keV) reached about 40 times
the Crab Nebula flux. Because of the exceptional interest of the flaring
activity from this source, observations at several wavelengths were conducted.
The MAGIC telescopes, triggered by the INTEGRAL alerts, followed-up the flaring
source for several nights during the period June 18-27, for more than 10 hours.
One hour of observation was conducted simultaneously to a giant 22 GHz radio
flare and a hint of signal at GeV energies seen by Fermi-LAT. The MAGIC
observations did not show significant emission in any of the analysed time
intervals. The derived flux upper limit, in the energy range 200--1250 GeV, is
4.8$\times 10^{-12}$ ph cm$^{-2}$ s$^{-1}$. We estimate the gamma-ray opacity
during the flaring period, which along with our non-detection, points to an
inefficient acceleration in the V404\,Cyg jets if VHE emitter is located
further than $1\times 10^{10}$ cm from the compact object.
