SIMFEROPOL (AFP) - Ukraine's ousted pro-Moscow president Viktor Yanukovych emerged defiant Thursday from five days in hiding as the country's new leaders issued a blunt warning to Russia against any aggression on the volatile Crimean peninsula.

Anxious Western governments voiced fears about the "dangerous" situation in Crimea after dozens of pro-Kremlin gunmen in combat fatigues seized government buildings in the autonomous republic and pleaded with Moscow not to escalate tensions.

Mr Yanukovych is to hold a press conference in Russia on Friday in his first public appearance since fleeing Ukraine at the weekend, Russian news agencies reported.

Russian President Vladimir Putin had stoked concerns Wednesday that Moscow might use its military might to sway the outcome of Ukraine's three-month standoff by ordering snap combat readiness drills near the border with the ex-Soviet state.

Interim president Oleksandr Turchynov responded by telling parliament that any movement of Russian troops out of their Black Sea bases in Crimea "will be considered as military aggression".

Ukraine's bloodiest crisis since its 1991 independence erupted in November when Mr Yanukovych made the shock decision to ditch an historic EU trade pact in favour of closer ties with old master Russia.

Mr Yanukovych, deposed at the weekend in a fast-moving drama after a week of bloodshed, broke his five-day silence by telling Russian news agencies from an undisclosed location he still viewed himself as president.

A high-ranking source quoted by the news agencies said the fugitive leader's request for personal security had been "granted on Russian territory", suggesting he was now there.

Ukraine had appeared to take a decisive swing back towards the EU by ousting Mr Yanukovych and replacing his entire pro-Russian team with a new brand of younger politicians who will steer the nation - torn between a Russified east and pro-European west - until snap presidential polls are held on May 25.

The Verkhovna Rada parliament confirmed opposition icon Yulia Tymoshenko's top ally Arseniy Yatsenyuk as prime minister by a near-unanimous margin and approved the makeup of his untested but strongly pro-Western government.

"Ukraine is being torn apart," a sombre Yatsenyuk said of the strategic but now splintered nation that has served as the geopolitical bridge between Russia and the West.

"But Ukraine sees its future in Europe. We will be a part of the European Union."