KIEV, April 14 (Xinhua) -- The Ukrainian government is considering the possibility to hold a nationwide referendum on the country's federalization to ease the tension in the east, acting President Oleksandr Turchynov said on Monday.
"We are not against holding the referendum," Turchynov told the lawmakers, referring to the Ukrainian interim authorities.
He suggested that the voting be held along with the presidential elections scheduled for May 25 if the parliament adopts a corresponding decision.
Turchynov hoped that the overwhelming majority of Ukrainians will support an "indivisible, independent and democratic" Ukraine during the voting.
A referendum on the country's federalization and greater independence from Kiev is the key demand of pro-Russia protesters, who took control of several administrative buildings in eastern Ukraine over the weekend.
Turchynov also said Kiev considers actions of pro-Russia activists in the Donbass region in eastern Ukraine as Moscow's "aggression."
"What is going on in Donbass is not confrontation between Ukrainians. It is hidden and sometimes not hidden aggression of Russia against our country," he said.
Describing Russia's reaction to Kiev's "counter-terror operation" in eastern Ukraine as "inadequate," he accused Kremlin of offering "public support for terrorist offence."
Turchynov ordered a "counter-terror operation" in eastern Ukraine after pro-Moscow activists seized several government buildings there, demanding closer ties with Russia.
On Monday, he spoke via phone with UN Secretary General Ban Ki-moon and suggested that the UN send peacekeepers to participate in the "counter-terror operation."
A Ukraine-UN mission would show the international community that "the Ukrainian officers act in accordance with the law during their anti-terror operations," he said.
According to the local 1+1 TV channel, at least four people were killed in a spate of violence between Ukrainian security forces and pro-Russia activists during the weekend.
Two security officers were shot dead by pro-Russia protesters at a police station in the industrial town of Slavyansk, the TV channel said, adding that armed pro-Russia protesters also opened fire at a private car in the town center, killing two civilians.
Local media also estimated that some 10 people were injured during the clashes, but there was no immediate comment from the government about the exact number of casualties.
Meanwhile, Russian Foreign Minister Sergei Lavrov denied Russia's involvement, saying Moscow is not interested in getting involved in Ukraine's domestic affairs.
"We don't interfere in Ukraine's internal affairs; this contradicts our interests," Lavrov told reporters in Moscow, saying there were no agents of Russian special services in Ukraine.
Commenting on reports that the United States, the European Union and Ukraine were going to present some evidence about Russia's alleged involvement in the situation in Ukraine during an upcoming meeting scheduled for Thursday, Lavrov said those evidence could be "quasi-facts."
Lavrov said those who encourage Ukrainian authorities to use force to suppress protests in the country's eastern regions should be held responsible for the consequences.
Also on Monday, the Organization for Security and Cooperation in Europe (OSCE) called for peaceful solutions to the crisis in eastern Ukraine through dialogue and negotiations.
"I urge all parties to move away from confrontation," OSCE Chairman Didier Burkhalter told reporters in Kiev.
Burkhalter said the Ukrainian government and the international community should unite their efforts to find a political solution to the ongoing crisis.
To de-escalate the situation, Kiev should promote a nationwide dialogue on the crisis inside Ukraine, he added.
In Paris, the Elysee said French President Francois Hollande and British Prime Minister David Cameron condemned the violence in Ukraine and called for restraint.
"They ... called for restraint and dialogue from all sides in order to allow for a de-escalation and to quickly find a peaceful solution to the crisis," the Elysee said in a statement after the two spoke by telephone.
"They expressed their support for the Ukrainian government in carrying out the reforms expected by the public and in organizing the May 25 presidential election under the best conditions," said the statement.
During a daily news briefing, Hua Chunying, a spokeswoman for the Chinese Foreign Ministry, called on relevant parties in Ukraine to keep calm and exercise restraint.
China urged all sides in Ukraine to fully consider the legitimate interests and concerns of all regions and all ethnic groups, and seek a way out through political dialogue, Hua said when asked to comment on the conflict in eastern Ukraine.
She added that China backs relevant parties to continue talks and consultation and will further push forward a political solution to the crisis.