People attend a rally in Independence Square in Kiev, February 26, 2014. [Photo/Agencies]

SIMFEROPOL/KIEV - Ukraine's protest leaders named the ministers they want to form a new government following the overthrow of President Viktor Yanukovich, as an angry Russia put 150,000 troops on high alert in a show of strength.

Unrest in Ukraine

President Vladimir Putin's order on Wednesday for soldiers to be ready for war games near Ukraine was the Kremlin's boldest gesture yet after days of sabre rattling since its ally Yanukovich was ousted at the weekend.

Moscow denied that the previously unannounced drill in its western military district was linked to events in its neighbour but it came amid a series of increasingly strident statements about the fate of Russian citizens and interests.

US Secretary of State John Kerry warned Moscow that "any kind of military intervention that would violate the sovereign territorial integrity of Ukraine would be a huge - a grave mistake".

With the political turmoil hammering Ukraine's economy, the central bank said it would no longer intervene to shield the hryvnia currency, which tumbled 4 percent on Wednesday and is now down a fifth since January 1. Wednesday's abrupt abandonment of Ukraine's currency peg sent ripples to Russia where the rouble fell to five-year lows and bank shares fell.

In Kiev, leaders of the popular protests that toppled Yanukovich on Wednesday named former economy minister Arseny Yatseniuk as their choice to head a new interim government.

In a display of people power, the so-called 'Euromaidan' council made its announcement of Yatseniuk, and candidates for other key ministries, after its members addressed crowds on Independence Square, cradle of the insurgency.