KIEV, Ukraine -- Pro-Russian insurgents have prevented at least half of the election districts in the embattled east of the country to prepare for Sunday's presidential election, a Ukrainian official says. Volodymyr Hrinyak, chief of the public security department at the Ukrainian Interior Ministry, said Saturday that 17 out of 34 district election commissions in the Donetsk and Luhansk regions are not operating because their offices have either been seized or blocked by armed men. Hrinyak's update was reported by the Interfax news agency. The insurgents have controlled parts of Ukraine for weeks. Following their declaration of independence earlier this month, they pledged to derail the vote which they regard as an election in "a neighboring country."
They remain defiant although Russian President Vladimir Putin said Friday that he is prepared to work with the election winner. Twenty-one candidates are competing to become Ukraine's next leader. Polls show billionaire candy-maker Petro Poroshenko with a commanding lead, but short of the absolute majority needed to win in the first round. His nearest challenger is Yulia Tymoshenko, the divisive former prime minister who is far behind. Most polls suggest Poroshenko would win a runoff ballot, which would be held on June 15. Fighting was reported Friday between pro-Russia separatists and government forces in eastern Ukraine as Kiev continued an offensive to try to halt the uprising. Associated Press reporters saw two dead Ukrainian soldiers near the village of Karlivka, and another body near a rebel checkpoint, both in the Donetsk region. A rebel leader said 16 more people died Friday in fighting there - 10 soldiers, four rebels and two civilians - but there was no immediate way to verify his statement. In Kiev, the Defense Ministry said 20 insurgents were killed in an attack on a convoy of government troops Thursday by about 500 rebels, the largest insurgent assault yet reported. The clash could not be independently confirmed and it was unclear why such a large attack in a populated region would have gone unreported for more than a day.