Russia's Foreign Minister Sergei Lavrov has told a news conference that a deadly gunfight early on Sunday near the Ukrainian city of Slavyansk was a crime and showed Kiev was not controlling "extremists". He also accused Ukraine of violating the Geneva accord, saying the United States should take responsibility for authorities in Kiev and that any attempts to isolate Russia will fail.

"The most important thing now is to prevent any kind of violence. This is the first point of the Geneva agreement, the first demand to all those confronting each other now in Ukraine. But in this and other aspects, the Geneva agreement is not being implemented, and moreover, steps are being taken - above all by those who seized power in Kiev - that crudely violate the Geneva agreement." Lavrov said.

Kiev and Moscow traded accusations over a deadly shooting on Easter Sunday morning, when at least three people were killed at a checkpoint manned by armed Pro-Russian activists near the eastern Ukrainian city of Slavyansk. Moscow and its allies accused Ukrainian nationalists of attacking the checkpoint while Kiev said Russia had provoked the violence.

In a later incident, the Ukrainian defence ministry said gunmen on motorcycles fired on an army checkpoint between Donetsk and Slavyansk shortly after dark on Sunday. The troops opened fire, wounding one attacker and capturing two.