SVIATOHIRSK, Ukraine - A truce called by the government to mark the Easter holiday was shredded early Sunday by a gunfight that left at least one dead and three wounded at a checkpoint occupied by pro-Russia militias outside a breakaway city in eastern Ukraine.
The Russian Foreign Ministry quickly seized on the clash as evidence that the new Ukraine government could not keep order and was violating an agreement signed last week in Geneva to de-escalate the conflict.
The mayor of Slavyansk, where the clash took place, appeared on a Russian TV news channel after the event to beg President Vladimir Putin to send "peacekeepers" into Ukraine to protect the population.
Leaders of the new Ukraine government fear that Putin is looking for an excuse that would allow him to take more direct action in eastern Ukraine, where many of the citizens speak Russian.
Ukraine's Interior Ministry in Kiev said two groups fought over a makeshift barricade of tires and barbed wire north of Slavyansk around 3 a.m. and that an investigation was ongoing.
Police in Slavyansk gave the Interfax news agency a higher death toll, saying that three men belonging to the so-called "Donetsk People's Republic," a political and militia group composed of separatists and others who oppose the new government in Kiev, were killed in the clash and that others fled with their wounded and dead.
It was difficult to independently establish who fought whom and exactly how many were dead or injured.
The shooting quickly stirred passions in eastern Ukraine, where groups of armed self-defense militias opposed to the new central authority in Kiev have taken over police stations and city halls along an arc of cities close to the Russian border.
Moscow quickly took the side of the pro-Russia activists. In a statement, the Russian Foreign Ministry said "innocent civilians" were attacked by "militants" of the an ultra-nationalist, far-right organization called Right Sector, which emerged as a paramilitary group during the protests in Kiev that ousted former Ukraine President Viktor Yanukovych and his government.
"The Russian side is enraged by the militant provocation, which is an indication of the reluctance of the authorities in Kiev to bridle and disarm nationalists and extremists," a ministry statement read.
The Russian Foreign Ministry said, "local residents seized the vehicles of the attackers in which they discovered arms, aerial maps of the area, and Right Sector paraphernalia."
A spokesman for Right Sector said the group played no part in the clash and instead charged that Russian special forces and intelligence officers had staged a provocation.
Hours after the shooting, the new self-proclaimed mayor of Slavyansk pleaded for help from Putin.
"Fascists and imperialists are trying to conquer us by killing and injuring civilians," said Vyacheslav Ponomarev, the mayor. "They want to make slaves from us. They are not negotiating with us - they are simply killing us."
The heated rhetoric arises as pro-Russia separatists have refused to abide by a settlement reached last week in Geneva among the United States, the European Union, Russia, and Ukraine seeking to de-escalate the conflict by offering general amnesty to those who surrender their weapons and abandon public buildings occupied in recent weeks.
It was difficult for non-Russian journalists to reach site of the armed clash on Sunday.