Russia Girds Troops, Alarming Ukraine

DONETSK, Ukraine — President Vladimir V. Putin of Russia on Saturday ordered troops across central Russia on combat alert and began surprise military drills, renewing concerns about a Russian buildup a day after Ukraine ordered a government cease-fire in the country’s troubled east.

The order for drills in Russia’s central military district, which does not border Ukraine, was announced by Defense Minister Sergei K. Shoigu and involves around 65,000 Russian troops, including several thousand members of an airborne unit.

The drills will last a week, officials said in comments carried by Russian state news agencies.

Ukraine and the United States have accused Russia of covertly supplying rebel forces in eastern Ukraine with fighters and heavy arms, including tanks and rocket launchers, in recent weeks.

On Friday, a senior Obama administration official said Russia had “redeployed significant military forces to its border with Ukraine.” The official said Russian special forces along the border were also providing support to rebel fighters in Ukraine.