Kiev and Karlovka, Reuters—Armed pro-Russian separatists and a Ukrainian militia group clashed in the east of Ukraine on Friday, leaving at least two dead and heightening tension ahead of a presidential election called to draw a line under six months of bloody upheaval.

Kiev’s pro-Western leaders hope Sunday’s poll will stabilize the former Soviet republic after street protests toppled Moscow-backed president Viktor Yanukovich, sparking a chain of events that has led to the worst Russia-West crisis since the Cold War.

But even as the authorities prepared for a vote billed as the most important in 23 years of independence from Moscow and promised a suspension of anti-separatist operations on election day, the clash suggested further violence may mar the event.

A Reuters correspondent saw two dead bodies after the three-hour firefight in the morning between Ukrainian self-defense fighters and separatists manning a checkpoint in a rural location west of the big industrial city of Donetsk.

Reports suggested a higher death toll was likely.

“We are determined that honest and transparent elections will take place,” interim Prime Minister Arseny Yatseniuk declared in talks with two European Union foreign ministers as the bloc’s foreign policy chief, Catherine Ashton, voiced support for Kiev and its election.

Yatseniuk added that, despite separatist plans to disrupt the poll in the eastern areas that they control, he believed the majority of people there were against the “terrorists” and condemned their actions.

But Russia’s President Vladimir Putin, speaking in St. Petersburg, said Ukraine was already in effect in the grip of civil war. “A civil war is raging through Ukraine. But why are we the ones who are being blamed for this?” he asked at an international business forum.

After Yanukovich’s overthrow in February, Russia annexed Ukraine’s Crimea region and stationed thousands of troops in combat readiness near the border with Ukraine.

It looks askance at Kiev’s leaders and their pro-Europe policies, which could take the former Soviet republic out of Moscow’s orbit and denies Kiev’s charges that it has fomented the separatist rebellions in the Russian-speaking east.

Big observer team

While Germany’s Angela Merkel appealed to Russia to accept the Organization for Security and Cooperation in Europe’s (OSCE) verdict on the Ukraine election, Putin sent mixed messages, saying he would work with the winner and wanted better ties with the West but fiercely criticizing US policy on Ukraine.

The United States and European Union have threatened new, tougher sanctions if they consider Russia has disrupted the Ukrainian election, but many European countries are reluctant to take such a step due to close trade links with Moscow.

The OSCE watchdog has sent a team of more than 1,000 observers to monitor an election in which Ukraine’s leaders say they expect a huge turnout that will offset the loss of voters in annexed Crimea and separatist-controlled parts of the east.

The man tipped to win, chocolate baron Petro Poroshenko, has urged voters to hand him an outright victory, suggesting that Ukraine’s deteriorating security situation might otherwise derail the election before a second round can be held.

If no candidate wins more than 50 percent of the vote on Sunday, a run-off will be held on June 15, in all likelihood pitting Poroshenko against ex-prime minister Yulia Tymoshenko.

The fierce firefight in the eastern Ukraine settlement of Karlovka underlined the fragility of the security situation.

“The main threat to the elections is the illegal carrying of weapons and the moving around of people. We do not see an end to this illegal activity,” state security chief Valentyn Nalivaychenko told journalists.

Friday’s clash, which came a day after at least 13 Ukrainian servicemen were killed in another firefight, did not involve the army, but instead two among several armed groups operating under various flags in the east.

Pro-Russian separatists, calling themselves the “Patriotic Forces of Donbass,” were manning a checkpoint, one of many set up by the rebels who have taken control of strategic buildings in several towns and proclaimed a “people’s republic.”

They clashed with self-defense fighters from a pro-Ukrainian militia called the “Donbass Battalion.”

It was unclear who attacked first. But the firefight, in which the pro-Ukrainian militia said separatists used grenade launchers and machine guns, lasted more than three hours, local residents said.

Bodies

A Reuters correspondent who visited the scene soon after the clash saw two dead men, both wearing black battle fatigues. One lay on his back by the roadside, the other lay some way away near a burned-out warehouse. He had a gunshot wound in his head.

Another fighter, dressed also in battle fatigues, was clenching his fists in pain as paramedics tended his leg wounds.

“A small unit was on the road doing reconnaissance and it ran into a roadblock where there were many more separatists than us. They opened sniper fire, they had armored personnel carriers and machine guns,” said Semen Semenchenko, commander of the pro-Ukrainian militia force.

He said the separatists included at least 15 Chechen fighters.

But the separatists said the pro-Ukrainian force, backed by members of Ukraine’s ultra-nationalist First Sector, opened fire first. Locals, who mostly stayed indoors once the shooting began in the early morning, had contrasting views of who was to blame.

A 52-year-old woman who gave only her first name, Valentina, laid the blame at the door of Kiev, which is using the Ukrainian army in an “anti-terrorist operation” against the separatists.

“Why do they [the Kiev authorities] do this? Why is Europe silent? Everybody was living normally but now everyone is interfering.”

Asked if she would vote on Sunday, Valentina said: “Who should I vote for—for people who are killing us and shooting at us? The answer is No!”

Alexei, in nearby Krasnomaisk, voiced an opposite view as he brought petrol to pro-Ukrainian self-defense fighters.

“All this is because these idiot separatists want to undermine the elections. But we will vote anyway. Out of 25 kids in my son’s school, only seven are for Ukraine, the others call my son ‘Banderovets,'” he said, using a pejorative label for Ukrainian ultra-nationalists.