One of the victims was Vladimir Rybak, Oleksandr Turchynov said. Rybak, who recently went missing, was a member of the local parliament and belonged to the President's political party.
"The terrorists who basically have taken the entire
Such crimes are committed with the support of Russian forces, he charged.
But a statement from a pro-Russian leader in Slaviansk rejects the President's claim, and highlights that there is a war of perceptions, too.
Vyacheslav Ponomaryov, the de facto mayor of Slaviansk, placed blame for the deaths on far-right Ukrainian nationalist extremists.
A pro-government party official told CNN that Rybak's family identified his body at the morgue Tuesday. But the competing claims persist.
Turchynov: Ukrainians want unity
Turchynov, meanwhile, had strong words for
A majority of Ukrainian citizens "are for a united, democratic
But Turchynov said Tuesday that "unfortunately, the
He cited the seizure of a police station Monday in the eastern city of
Meanwhile, a statement from the prosecutor general's office in Kiev criticized law enforcement agencies in a number of cities in eastern Ukraine for not resisting pro-Russian protesters as they seized administrative buildings -- even in cases where they outnumbered the militants.
The statement says self-defense groups in these places were established in reaction to the failings of the security forces. "These defense groups have the right to bear arms and promise to guarantee public order in their respective regions," it said.
Turchynov's government has talked tough but done little to curb pro-Russian activities in the east, possibly afraid that a crackdown could send Russian forces across the border, U.S. Secretary of State John Kerry said. At the same time, the occupation of buildings continues in about a dozen towns and cities across eastern
In three towns, pro-Russian protesters and militants have made it clear to CNN they have no intention of moving until the "illegal" government in
Moscow also says the government in Kiev, installed after ousted President Viktor Yanukovych fled Ukraine for Russia in February, is illegitimate and backed by far-right extremists.
Yanukovych's ouster followed months of street protests prompted by his decision last November to drop a planned EU trade agreement in favor of closer ties with