Ukraine's military accused Russia on Friday of sending a column of 32 tanks and truckloads of troops into the country's east to support pro-Russian separatists fighting government forces.
Pro-Russian separatists will vote to set up a breakaway regional leadership in eastern Ukraine on Sunday aiming to take their war-torn region closer to Russia and defying Kiev and the West as the big guns still boom across the territory.
German Chancellor Angela Merkel told Russian President Vladimir Putin on the phone that Sunday's planned elections in eastern Ukraine were illegitimate and would not be recognized by European leaders, a Berlin government spokesman said on Friday.
President Petro Poroshenko called on Ukrainians on Saturday to elect a majority on Sunday that would see through a pro-Europe, reform agenda and break with the Soviet past.
Ukrainian President Petro Poroshenko said on Saturday he expected planned talks with Russia's President Vladimir Putin next week in Italy to be difficult but said Moscow had a crucial role to play in bringing peace to his country.
On the first day of school outside the east Ukrainian rebel stronghold of Donetsk, 11th-grade teacher Yelena Sepik tells her class to get out of their seats to clap and sing along to the Soviet military music playing over the speakers.
Ukrainian President Petro Poroshenko has secured a temporary peace in the troubled east which he says gives him a chance to move Ukraine towards its dream of a place in Europe - but Russia's Vladimir Putin still holds cards that could thwart him.
The Ukrainian city of Donetsk was rocked by blasts on Saturday, even as government forces and pro-Russian separatists prepared to create a buffer zone to separate the warring sides.
Ukraine ratified a sweeping agreement with the European Union on Tuesday - an issue at the heart of the Russia-West crisis over its future - and sought to blunt the independence drive of Russian-backed separatists by offering them temporary and limited self-rule.
Ukraine's defense minister said on Sunday that NATO countries were delivering weapons to his country to equip it to fight pro-Russian separatists and "stop" Russian President Vladimir Putin.
Five Ukrainian servicemen have been killed in the past four days, the military said on Tuesday, underscoring the strains in a ceasefire between government forces and pro-Russian separatists that officials insist is still broadly holding.
The Russian Foreign Ministry accused Ukrainian forces on Wednesday of responsibility for the "barbarous" killing of a Russian photojournalist and demanded an investigation.
