More than 45,000 people have been evacuated from 200 "targets" in dozens of Russian cities after a wave of anonymous bomb threats were made over the past three days, amid speculation of either foreign interference or a domestic anti-terror drill.
Today, 15,000 people were evacuated from places in Moscow, including Red Square, after calls were made to shopping centres, three railway stations and at least four universities.
Anonymous callers are reported to be using the internet to alert emergency services or facilities directly, claiming places had explosive devices hidden inside.
Since Tuesday dozens of schools, universities, shopping centres, railway stations, airports and government offices have been evacuated and inspected by police in 29 cities all over Russia - from Kaliningrad in the west to Vladivostok in the far east.
No traces of explosive devices have been found in any of the buildings, the Meduza news outlet reported.