Voter turnout in Bulgaria was bigger in the morning in Sunday's presidential election compared to the last vote, data from election authorities shows.

The activity was 10.23% (nearly 700 000 people) in the election and 8.68% (more than 593 000) in the referendum as of 10:00 local time (EET).

In the previous election, it was around 7% at that hour, with polling stations having opened at 06:00 then, an hour earlier compared to Sunday. Officials say the figure is higher than the one registered in all elections over the past several years.

Voting was made compulsory in Bulgaria earlier this year, Sunday's vote being the first one where new rules are applied.

Few violation claims have been submitted to authorities as of 10:00 local time during the presidential election on Sunday, the Central Election Commission (CEC) says.

"Voting goes in an uninteresting manner," Darik Radio quotes CEC head Tsvetozar Tomov as saying.

Twenty-two claims of violation have been registered across more than 12 000 polling stations as of 10:00, three hours into the vote, according to another CEC official, Kameliya Neykova.

Of these, 18 are related to organizational issues at the regional and local election committees, while four are linked to breaches of voters' rights.