Moscow/Kiev, Rajab 30, 1435, May 29, 2014, SPA -- Pro-Western billionaire Petro Poroshenko was confirmed the winner of Ukraine's presidential election on Thursday amid fresh fighting in the country's east, dpa reported. Poroshenko won Sunday's vote with 54.7 per cent, the election commission said after counting all ballots. Parliamentary speaker Oleksandr Turchynov, who has been the acting head of state since Viktor Yanukovych's ouster in February, said he had ordered the preparations for Poroshenko's inauguration ceremony. Poroshenko's office said later that the ceremony will be held on June 7, the Interfax Ukraine news agency reported. Turchynov also confirmed a victory for former boxing champion Vitali Klitschko, a Poroshenko supporter, in the race for mayor of Kiev. Tensions in eastern Ukraine escalated again when pro-Russian separatists shot down a military helicopter near the embattled city of Sloviansk, killing at least 12 people. The Mil-8 transport helicopter was hit by a shoulder-fired missile as it returned from a troop rotation flight, Ukraine's National Guard said. It added that one of the 13 servicemen on board survived with heavy injuries and that among those killed was National Guard General Serhiy Kulchytskiy. Vyacheslav Ponomaryov, the self-declared mayor of Sloviansk, confirmed that the helicopter was downed by his men. He denied the National Guard's claim that it had subsequently killed the attackers, saying that all members of the group had returned to their base, Russian news agencies reported. -- SPA 21:18 LOCAL TIME 18:18 GMT www.spa.gov.sa/1238168