The main rebel leader in Ukraine's largest separatist region won a crushing victory in a controversial election Ukrainian president Petro Poroshenko labelled "a farce".

Prime minister of the self-declared Donetsk People's Republic, Alexander Zakharchenko, won over 81 per cent of the vote in the presidential poll, rebel election chief Roman Lyagin said.

His party was also set to claim 65 per cent of the parliamentary vote, in an election designed to bring a degree of legitimacy to the makeshift military regimes that already control them.

"These elections are important because they will give legitimacy to our power and give us more distance from Kiev," Mr Lyagin said.

The United States and European Union have denounced the vote as illegitimate, and EU foreign policy chief Frederica Mogherini described it as an "obstacle to peace" in Ukraine.

"I consider today's 'presidential and parliamentary elections' in Donetsk and Luhansk People's Republics a new obstacle on the path towards peace in Ukraine," she said.

Russia however said it would recognise the result, which is sure to stoke tensions further between the West and Russia.

Mr Zakharchenko accused Kiev of rejecting peace after claiming victory in the election.

"Ukraine does not want peace, as it claims. Obviously it is playing a double game," he said.

Ukrainian authorities said they would be opening a criminal investigation into the elections, calling them an illegal "power grab".

"The holding of so-called elections on November 2 contradicts" the constitution and resembles "a power grab", the security service of Ukraine said in a statement. "A criminal probe has been opened."





Ahead of the poll, Ukrainian president Petro Poroshenko blasted the election as a violation of an already tattered truce deal signed on September 5.

He called the polls "pseudo-elections that terrorists and bandits want to organise on occupied territory", and "a farce, (conducted) under the barrels of tanks and machineguns".

Across the region, suffering from years of neglect and months of war, people stood in freezing temperatures to cast their vote as shelling continued across the territory.

"We are citizens of Donetsk, and we don't want to live under the Kiev government that has turned its back on us," private security guard, Sergei Kovalenko said.

No international election monitors were present for the vote, and no minimum turnout had been set by the organisers, reflecting the uncertainty over how many voters could turn out.

"For justice, happiness, peace and prosperity"

Mr Zakharchenko's campaign advertisements were plastered across Donetsk in the lead up to the election.

Using colourful language in a heavy local accent, Mr Zakharchenko, 38, compared the region's coal deposits to the oil reserves in the United Arab Emirates and has promised pensioners a stipend that will allow them to go on safari in Australia.

Wearing a dark suit rather than his usual military fatigues, Mr Zakharchenko dropped his vote into a ballot box at a polling station at a local school: "For justice, happiness, peace and prosperity".

"He doesn't eat, he doesn't sleep. He works only for us 150 per cent of the time," Lyudmila Kovalenko said, who works at a school.

She said the rebel leadership had fixed the windows of the school after it was hit by a mortar.

Mr Zakharchenko's election as rebel leader will mean little by way of change for the region which is increasingly dependent on Russia for support financially and politically.

Enthusiasm for the rebel cause, which was at its peak in Ukraine's Russian-speaking east following the ouster of Moscow-backed Viktor Yanukovich, waned after violence closed banks and many stores, forcing people out of work.

Voting stations drew a steady stream of people on Sunday, but many Donetsk residents said the vote would change nothing and questioned its validity given there are no voters lists.

"I don't see why I should vote. It won't change anything, and besides the election isn't for the people of Donetsk. It's for the rebels themselves," Vitaly, 34, said.

Kiev claims 'intensive' movements of troops crossing from Russia

Meanwhile, the Ukrainian military reported "intensive" movement of troops and equipment from Russia into the separatist controlled parts of eastern Ukraine on Sunday.

"There is intensive deployment of military equipment and personnel of the enemy from the territory of the Russian Federation onto territory temporarily controlled by insurgents," Ukrainian military spokesman Andriy Lysenko told a briefing in Kiev.

In Donetsk, AFP reporters saw about 20 trucks, some carrying anti-aircraft guns, heading towards the government-held airport, although it was not clear whether these were new forces.

Several Western news outlets reported witnessing heavy movement of troops near Donetsk.

Russia has repeatedly denied accusations from Kiev, Western governments and the NATO alliance that it is fighting on the side of pro-Russian separatists who have taken over a swathe of Ukraine's industrial south-east.

Rebel leaders said they intend to expand their territory as far as the Azoz Sea port of Mariupol.

Russian troops already occupy Ukraine's southern province of Crimea, which has been declared a part of Russia.

The province was taken over almost without a fight when large numbers of heavily armed men in unmarked uniforms quickly surrounded demoralised Ukrainian troops in March.

The troops, widely dubbed "little green men", were later confirmed to have been Russian regular troops.

The war has killed more than 4,000 people, including more than 300 in the last two weeks.

Reuters/AFP