A series of phoned-in bomb threats that have already affected up to a million people across Russia continued on Wednesday with such calls prompting mass evacuations in three cities.

MOSCOW (Sputnik) — Around 16,000 people have been evacuated over the past 24 hours in three Russian cities, including Moscow, after bomb threat calls were made to over 70 buildings, a source in the emergency services told Sputnik on Wednesday.

Multiple calls claiming that explosives have allegedly been planted in various public facilities have been made across Russia for about a month. According to the source, over 1 million people have been evacuated in 170 of Russia's cities during this period due to the threats.

Neither of the claims has been confirmed, even after police had examined the buildings.

A law enforcement source told Sputnik that the calls were made from abroad by persons associated with the Daesh terrorist group , which is banned in Russia.

Alexander Bortnikov, director of the Russian Federal Security Service (FSB) has estimated that the first days of calls alone resulted in damages worth over 300 million rubles (about $5.2 million). According to the official, the threats have been made by four Russian citizens from abroad.

Kremlin spokesman Dmitry Peskov called the situation "telephone terrorism," adding that all the necessary measures were being taken to find the perpetrators.