Bangkok, March 24 -- Voters in Thailand were heading to the polls Sunday in the country's first election since the military ousted an elected government in a 2014 coup.

Prime Minister Prayuth Chan-ocha, the army chief who led the coup, is hoping to extend his hold on power after engineering a new political system that aims to stifle the influence of big political parties not aligned with the military.

About 51 million Thais are eligible to vote. Leaders of political parties opposed to military rule have urged a high turnout as the only way to derail Prayuth's plans.

The junta leader was among the first to vote in the Thai capital Bangkok, arriving in a Mercedes, after polling booths opened at 8 a.m.

Speaking to reporters after casting...