Ukraine plunged further into crisis yesterday after unidentified pro-Russian gunmen seized Crimea’s regional parliament, prompting legislators there to call a referendum on the peninsula’s future.

The raid in Simferopol, Crimea’s capital, intensified east-west tensions over Ukraine. Fears mounted that separatists could prevail in the largely pro-Russian autonomous peninsula after a pro-western leadership assumed power in Kiev following last week’s toppling of president Viktor Yanukovich.

The developments came as Arseny Yatseniuk, Ukraine’s new prime minister, declared that tens of billions of dollars had been looted from the state, and in a statement released in Russia, Mr Yanukovich claimed that he was still the country’s rightful president.