Kiev accused Moscow today of seeking to trigger a "third world war" as military tensions soared in east Ukraine and US President Barack Obama led a diplomatic charge against Russia.
A rocket-propelled grenade blew up a Ukrainian military helicopter sitting on the tarmac at a base near the eastern town of Kramatorsk, officials in Kiev said. The pilot escaped but was wounded. Smoke spewed in the sky over the nearby rebel-held town.
The brazen attack by the insurgents came amid an army offensive to dislodge pro-Kremlin gunmen who are holding a string of eastern towns.
Kiev announced today that its forces were now seeking to "blockade" rebels inside another flashpoint town, Slavyansk, to prevent militant reinforcements arriving.
Yesterday, Ukrainian armoured vehicles and commandos had made a brief but dramatic incursion into Slavyansk, killing one 22-year-old insurgent.
Russia responded by ordering its troops massed on Ukraine's border to launch a new military exercise.
The developments prompted German Chancellor Angela Merkel to call Russian President Vladimir Putin to voice "great concern" over the situation and to urge implementation of a Geneva accord signed a week ago that was meant to defuse tensions.
Merkel's spokesman Steffen Seibert also warned of fresh sanctions against Russia, telling reporters in Berlin: "Sanctions are already in place... You have to face the facts -- in case nothing changes -- it is important to be prepared for more."
Ramping up the Cold War-style rhetoric, Ukrainian Prime Minister Arseniy Yatsenyuk accused Russia of trying to spark a global conflict.
"The world hasn't forgotten the Second World War and Russia wants to start a third world war," he said.
"Russia's support for the terrorists in Ukraine constitutes an international crime and we call on the international community to unite against the Russian aggression."
US Secretary of State John Kerry said the Kremlin was making an "expensive mistake" by meddling in Ukraine, stressing that further Western sanctions on Moscow were poised to be unveiled.
Moscow, Kerry said, was trying to "actively sabotage the democratic process through gross external intimidation", described the latest Russian drills as "threatening".
