(Adds Russia saying 150,000 personnel involved, drill not linked to Ukraine events, will protect Black Sea Fleet)
By Steve Gutterman
MOSCOW, Feb 26 (Reuters) - President Vladimir Putin ordered an urgent drill to test the combat readiness of his armed forces across western Russia on Wednesday, flexing Moscow's military muscle amid tension with the West over Ukraine.
Russia said the exercises were not linked to events in Ukraine, where the ouster of a president who turned his back on the European Union and sought closer ties with Moscow has raised worries in the West over possibility of military intervention.
Putin has ordered several such surprise drills in different Russian regions since he returned to the presidency in 2012, saying the military must be kept on its toes, but the crisis in the neighbouring nation gave them added geopolitical resonance.
"In accordance with an order from the president of the Russian Federation, forces of the Western Military District were put on alert at 1400 (1000 GMT) today," the Interfax news agency quoted Defence Minister Sergei Shoigu as saying.
Shoigu said the training drills were not linked to events in Ukraine, and Deputy Defence Minister Anatoly Antonov said they had been previously planned. He said they would involve about 150,000 military personnel.
The western district encompasses most of western Russia and borders Ukraine, which lies between NATO nations and Russia.
Forces must "be ready to bomb unfamiliar testing grounds" as part of the drill, Shoigu told a Defence Ministry meeting.
Putin has made no public comment on Ukraine since President Viktor Yanukovich was driven from power over the weekend. His ouster came after months of political turmoil that began when he spurned deals with the European Union and sought to improve ties with Russia.
The United States and European nations have warned Russia against military intervention in Ukraine, a former Soviet republic that Putin has called a "brother nation" and wants to be part of a Eurasian Union he is building in the region.
Russian officials have said Moscow will not interfere in Ukraine, while accusing the West of doing so. Interfax cited the speaker of the upper parliament house, Valentina Matviyenko, as saying on Wednesday it would not use force.
But Prime Minister Dmitry Medvedev said on Monday that Russia's interests and its citizens in Ukraine were under threat, language reminiscent of statements justifying Russia's invasion of Georgia in 2008, when he was president.
Shoigu said the drill would be conducted in two stages, ending on March 3, and also involved the command centres of Russia's Air and Space Defence forces, paratroops and long-range aviation as well as some troops in central Russia.
In the two-day first stage, military units would be brought to "the highest degree of combat readiness" and would be deployed to testing areas on land and sea, Interfax quoted Shoigu as saying.
The second stage would include tactical exercises and involve warships from the Northern and Baltic Fleets, he said, and some warplanes would move to combat airfields.
Descriptions of the exercises did not mention the Black Sea Fleet, which is based in Sevastopol in Crimea. Tension over Ukraine's turmoil is high because of the fleet's presence and the region's large ethnic Russian population.
In separate comments, Shoigu said Russia was "carefully watching what is happening in Crimea" and was taking unspecified measures to ensure the security of the facilities and arsenals of the Black Sea Fleet, state-run RIA reported.
Shoigu said the drill would also test the counter-terrorism measures in place at military units. Russian officials have referred to some of the Ukrainian opposition forces whose protests pushed Yanukovich from power as "terrorists".
(Writing by Steve Gutterman and Thomas Grove, editing by Larry King)