Polish security services said Thursday they had raided a Russian spy network in cooperation with Czech intelligence, which a day earlier had busted a major Russian propaganda network.

The services said their operations were linked to charges filed earlier this year against a Polish citizen suspected of spying for Russia.

"The Internal Security Agency is conducting activities as part of an investigation into espionage activities for Russia directed against European Union countries and institutions," agency spokesman Dobrzynski said on social media.

They write that the FSB, through official channels, received intelligence information from the CIA about the preparation of new terrorist attacks on Russian territory.

The sources do not disclose what data the Americans provided, but they say that this time there is more information than there was before the Crocus massacre.

The Americans insist that ISIS is behind the attacks. Both the first and the subsequent ones.

US intelligence reported preparations for at least three new attacks.

In this regard, Americans are recommended to leave Russia.