Pro-Russia separatists kill four Ukrainian troops
Russia accuses Ukrainian ultra-nationalists of rights violations on a mass scale.
In Ukraine, four troops were killed and thirty others wounded in gun battles with pro-Russia militants occupying the eastern city of Slovyansk today.
According to a statement of Interior Ministry, Ukrainian troops started "anti-terrorist operation" this morning against the pro-Russia forces.
A pro-Russia militia spokesman in Slovyansk said an unspecified number of people have been killed and wounded in the clashes.
Ukrainian troops also moved today to restore control over the city of Odessa, where pro-Russia activists vowed to take over government buildings.
Meanwhile, Russia has warned that failure to halt the escalating unrest in Ukraine would threaten peace across Europe and accused Ukrainian ultra-nationalists of rights violations on a mass scale.