Almost 900,000 people cast ballots during the day, The Bangkok Post reported.

Turnout was heavy in Bangkok. But a lot of people also voted in three southern provinces where there had been fears that insurgents would try to disrupt the election.

Voters were allowed to register to cast ballots this weekend instead of Dec. 23. Soldiers, who are likely to be on duty on the official election day, registered and voted in significant numbers.

Election Commissioner Praphan Naikowit, who voted Saturday, said there were few major problems reported. The high turnout took officials at some polling stations by surprise.

"People were active in casting their ballots. They went to the polling booths early this morning. I assure you that the Dec. 23 polls will not be postponed," the commissioner said.