Berlin will send over 500 troops to Lithuania for military exercises this year to underscore its NATO commitments amid tensions with Russia, the Baltic state's defense ministry said Tuesday.

A company of soldiers will be deployed to the formerly Soviet-ruled Baltic state from April to July, and separate units will arrive for exercises in July and November, the ministry said in a statement.

Three soldiers were killed and five injured in eastern Ukraine, an army spokesman said Tuesday, further undermining a month-old ceasefire between government forces and pro-Russian separatists.

Some of the casualties were caused by fire from the rebels, the others occurring when a military vehicle drove over a landmine, spokesman Andriy Lysenko told reporters.

Russia will deploy Tupolev nuclear-capable bomber jets to Crimea in a snap drill, a defense ministry source said Tuesday, as the peninsula marks a year since its annexation by Moscow.

"As part of a snap check of combat readiness of the armed forces, Tupolev 22-M3 strategic missile-carriers will be deployed to Crimea," the source told Russian news agencies, without giving a specific date.

Ukraine on Monday said it will vote this week on bills granting separatist areas in the east special status in line with a February peace deal, as one soldier died in continuing sporadic clashes.

The bills, submitted by President Petro Poroshenko to parliament at the weekend and whose text became available Monday, fall in line with the commitments by Kiev in the ceasefire deal inked on February 12 in Minsk.

Crimea kicked off celebrations Monday to mark one year since a controversial vote that led to Russia's annexation of the peninsula, a historic shift blasted by the West and Ukraine as an illegal takeover.

Fireworks and concerts were planned in the Black Sea peninsula for the festivities a year after the controversial poll saw residents vote under the watchful eye of elite Russian troops in unmarked uniforms who had swarmed key sites in Crimea two weeks earlier.

Russia is gearing up to celebrate the one year anniversary on Monday of Crimea voting to leave Ukraine and join the Russian state in a takeover blasted as illegal in the West but seen at home as a triumph for Vladimir Putin.

The hastily organized March 16, 2014 referendum -- which Putin now admits came well after he'd already taken the decision to seize the Black Sea peninsula from Kiev -- kickstarted a bloody separatist conflict in eastern Ukraine and sent Moscow's relations with the West into a tailspin.

In eastern Ukraine's rebel-held city of Donetsk workers at a factory that used to supply heavy machines for local coalmines are busy spray painting armored vehicles and fixing tank tracks.

The Corum Donetskgormash plant is a hive of activity, with the clang of tools ringing out above the incessant coming and going of trucks.

Ukrainian doctors have visited pilot Nadiya Savchenko in her Moscow prison for the first time since her capture nine months ago, Ukraine's government said Saturday.

"Thanks to joints efforts of many, from @ poroshenko (President Petro Poroshenko) to our consul in Moscow, Ukrainian doctors are now with Nadiya," Foreign Minister Pavlo Klimkin tweeted under the #FreeSavchenko hashtag.

Ukrainian President Petro Poroshenko confirmed Friday a "gradual de-escalation" in fighting between government forces and pro-Russian separatists, a month after a ceasefire agreement came into effect.

"The fact that we have not had military losses for several days... is a clear indication of a gradual de-escalation," Poroshenko told Ukraine's private 1+1 television network.

Russian President Vladimir Putin said he'd spent more enjoyable evenings. German Chancellor Angela Merkel talked of a "glimmer of hope" but said she was under "no illusions".

A month after the ceasefire deal which she and French President Francois Hollande thrashed out with Putin and his Ukrainian counterpart Petro Poroshenko at marathon overnight talks in the Belarus capital Minsk in February a peace of sorts is holding in eastern Ukraine.