The head of Georgia’s election commission was splashed with paint as the body confirmed the ruling party’s victory in the parliamentary elections. David Kirtadze, a member of the former president Mikheil Saakashvili’s United National Movement (UNM), splashed black paint on the central election commission chair, Giorgi Kalandarishvili, on Saturday, resulting in an eye injury, a video broadcast on local TV channels showed. Hundreds of opposition supporters staged a rally outside the commission’s headquarters during the session. The ministry of internal affairs said it had launched an investigation into the incident. Kalandarishvili came back to the meeting with a plaster on his left eye, having signed a protocol that confirmed the ruling pro-Russian Georgian Dream party as the winner of the 26 October election. The party received 53.9% of the vote, winning 89 seats in a 150-seat parliament, Georgian media reported. After the ballot, supporters of opposition parties staged several protests in Tbilisi, alleging election fraud. The Caucasus country’s pro-western opposition has denounced the 26 October vote as “fraudulent”, while the EU and the US have called for an investigation into alleged electoral “irregularities”. The Georgian president, Salome Zourabichvili, who is at loggerheads with the governing party, has also described the vote as illegitimate and accused Russia of interference. Moscow has denied meddling. She joined the opposition’s calls for a fresh vote, saying she would not issue a decree to convene the new parliament. Tens of thousands of people have taken to the streets in Tbilisi to protest against alleged electoral fraud. Universities in big cities across Georgia were gripped by student protests on Friday evening. The prime minister, Irakli Kobakhidze, has insisted the elections were free and fair and said parliament would convene within 10 days after the release of the final results – even without a presidential summons from Zourabichvili. Last week, Kobakhidze threatened to ban all the main opposition parties – “if they persist in actions that violate the constitution” – despite his party’s failure to secure the 113-seat constitutional majority it had sought in order to enact such a ban. A group of Georgia’s leading election monitors has said they had uncovered evidence of a complex scheme of large-scale electoral fraud that swayed results in Georgian Dream’s favour. The US pollster Edison Research, whose exit poll had predicted victory for opposition forces, has said the discrepancy between its forecast and official results “cannot be explained by normal variation” and “suggests local-level manipulation of the vote”. All of Edison’s previous exit polls conducted since 2012 in Georgia were in line with official results, and its exit poll models used in Georgia this year were the same ones used in US presidential election exit polls for ABC, CBS, CNN and NBC. Earlier this month, the EU Council chief, Charles Michel, said “there are serious suspicions of fraud, which require a serious investigation”. Georgia is an EU candidate country, and before the election, Brussels had warned the vote would determine its chances of joining the bloc.