Pro-Russian rebels shot down two Ukrainian helicopters on Friday, killing two crew, as troops tightened their siege of separatist-held Slaviansk and Moscow accused Kiev of launching a "criminal" assault that wrecked hopes of peace, according to The Associated Press.
Ukrainian forces appeared to be carrying out one of their most concerted military operations yet, their advance on the ground was limited, but President Vladimir Putin's spokesman accused Kiev of firing on civilians from the air in a "punitive operation" that destroyed an international peace plan, the AP reported.
Russia was "extremely worried" about the fate of Russians in the city, including an envoy sent to help free German and other foreign hostages, the Kremlin spokesman said, according to the AP.
The dramatic language seems to raise the stakes, as Moscow has tens of thousands of troops massed on the border and claims the right to invade if needed to protect Russian speakers, the AP reported.
Reuters journalists in Slaviansk, the most heavily fortified bastion of pro-Russian separatists in eastern Ukraine, heard shooting break out and saw one helicopter opening fire before dawn, according to the AP.
Ten hours later, the city was largely quiet, with shops shut and armed separatists in control of the streets, the AP reported. Advancing Ukrainian forces in armored vehicles took up positions closer in to the suburbs, but rebels still controlled most of the city of 130,000.
The separatist pro-Russian militants also made more moves on Thursday, seizing a rail control center for the Donetsk region, a railway official said, according to the AP.
Kiev said the firing of missiles that brought down its helicopters was evidence that Russian forces were present in the town. Moscow denies that its troops are on the ground, the AP reported.
Kremlin accounts of grave threats to civilians highlight the risk of a Russian move to seize territory ahead of a vote the rebels aim to hold on May 11 seeking a mandate to break with Kiev, like one held in the Crimea region before Moscow annexed it in March, according to the AP.
For Russians, the Kremlin's rhetoric of "fascists" in Kiev launching a "punitive operation" evokes the depredations of Nazi German invaders in World War Two, being given extensive state media coverage as next week's anniversary of the Soviet victory is used to foster national pride and nostalgia, the AP reported.
