(Recasts with Transdniestria exercises)
MOSCOW, March 25 (Reuters) - Russia's military staged training exercises on Tuesday in Transdniestria, a breakaway sliver of Moldova that is a focus of tension following Russia's annexation of Ukraine's Crimea region.
NATO's top military commander said on Sunday he was worried that Russia might have its eye on Transdniestria, a largely Russian-speaking region that borders western Ukraine, after seizing Crimea, which has a narrow ethnic Russian majority.
The Interfax news agency quoted a spokesman for Russia's Western Military District, Colonel Oleg Kochetkov, as saying that Russian forces stationed in Transdniestria had "conducted an anti-terrorism drill and practised operations to rebuff an attack on their military base".
Transdniestria, with a population of half a million, has run its own affairs since 1992 after fighting a brief war against the Moldovan government over fears that it might join Romania after the collapse of the Soviet Union, and Russia has a permanent garrison of peacekeepers there.
Russia has held several military drills during months of political upheaval in Ukraine. Some have brought large Russian forces close to Ukraine's eastern border, adding to concerns of an invasion after President Vladimir Putin secured permission from parliament to send in troops to protect Russians if needed.
Earlier on Tuesday, a spokesman for Russia's Strategic Rocket Forces, responsible for Russia's long-range nuclear arsenal, said around 10,000 troops would take part in exercises until March 29 in western Siberia's Omsk region and Orenburg in the southern Urals, more than 2,000 km (1,200 miles) from Russia's border with Ukraine. (Reporting by Vladimir Soldatkin and Steve Gutterman; Editing by Kevin Liffey)