IRKUTSK, April 16 (RIA Novosti) - Voter turnout at Sunday's referendum in the Ust-Ordynsky Buryat Autonomous Area in Siberia on its merger with the Irkutsk Region has passed the required threshold, the local electoral commission said.

As of 16:00 p.m. local time (07:00 a.m. GMT), about 60% of registered voters had come to the polls in the Ust-Ordynsky Buryat Autonomous Area, crossing the electoral threshold of 50%, the commission said.

The Irkutsk Region electoral commission said 48.36% of electors had voted in the region by that time. Voting in the Ust-Ordynsky Buryat Autonomous Area will last until 20:00 p.m. local time (15:00 p.m. GMT) while polling stations in the Irkutsk Region will close two hours later.

The referendum requires more than 50% of the voters in each of the two regions to come to the polling stations to validate the polls.