The head of Ukraine's security services has said that Ukraine is a victim of cyber attacks.
Government phones have been tapped and illegal telecommunications equipment has been installed in Crimea, he said.
Pro-Russia activists recaptured administrative headquarters in the Ukrainian city of Donetsk and flew the Russian flag from its roof.
ITV News' Europe Correspondent describes the tense atmosphere surrounds a central government building in Donetsk .
New footage obtained by ITV News shows Russian troops firing warning shots as Ukrainian soldiers approached during a tense stand-off today.