More than half of Kyrgyzstan's eligible voters had gone to the polls in Sunday's referendum on a new constitution by 18:00 local time (12:00 GMT), the country's Central Election Commission said.
With two hours of voting remaining, turnout was 53.12 percent, or 1.47 million people, according to election officials.
There is no minimum turnout required to make the referendum valid.
The proposed new constitution would give more power to parliament, turning the presidency into a largely ceremonial role and making the country a parliamentary republic.
The vote is also an important test of public confidence in the interim government, which took power in April after the violent ouster of President Kurmanbek Bakiyev. The new constitution needs to be approved by 50 percent plus one of ballots cast to come into effect.
The polls are taking place despite the deadly interethnic clashes that began in the country's southern city of Osh on June 11 and spread to the nearby Jalal-Abad region. Government figures updated on Sunday put the death toll at 283 but Kyrgyz officials acknowledge that the real number of victims may be 10 times higher.
The highest turnout - 67.7 percent - was recorded in the Chui region, which includes the capital, Bishkek. The lowest was in the Jalal-Abad region, where 41.32 percent of the electorate had voted by 18:00. In Osh and the surrounding region turnout had reached about 45 percent.
Election commission member Galina Skripkina said preliminary results of the referendum would appear at 21:00 local time (15:00 GMT).
According to the election commission, 189 observers from 18 international organizations, including the Commonwealth of Independent States, the Shanghai Cooperation Organization and the Organization for Security and Cooperation in Europe, were monitoring the polls.
All 2,281 polling stations in the country opened on Sunday, while there were 38 more for Kyrgyz citizens abroad. Around 7,500 police officers and the same number of voluntary helpers were deployed to ensure security during the vote.
The referendum on a new constitution is a major part of the plans of the interim authorities in Kyrgyzstan to return the country to democratic rule. The government, led by Roza Otunbayeva, came to power amid April's large-scale opposition protests, which overthrew Bakiyev. The ousted president has since taken refuge in Belarus.
BISHKEK, June 27 (RIA Novosti)
