UPDATE April 17, 6:13 a.m. EST:
The Turkish opposition party is demanding a partial recount after Sunday's constitutional referendum that consolidated power to the office of the president, citing irregularities in the voting process, Al Jazeera reports.
Kemal Kilicdaroglu, leader of the Republican People's Party (CHP), said he respects the electorate but criticized the election board's decision to bcount ballots that didn't have an official stamp. 51.4 percent of voters supported the referendum.
Millions of Turks voted Sunday on a controversial referendum that would give sweeping new powers to the country's president, Recep Tayyip Erdogan.
The new draft constitution is an 18-article reform package put forward by the ruling Justice and Development Party that would replace the current system of parliamentary democracy with a powerful executive presidency.
Turkey's state-run Anadolu news agency says with 57 percent of ballots counted, the "yes" votes are leading with 56.5 percent for expanding the president's powers.
Erdogan and his supporters say the "Turkish-style" presidential system would bring stability and prosperity in a country rattled by a coup attempt last year and a series of devastating attacks by the Islamic State group and Kurdish militants.
Opponents fear the changes will lead to autocratic one-man rule by the 63-year-old Erdogan, who has been accused of repressing rights and freedoms.
More than 55 million people of about 80 million were registered to vote and more than 1.3 million Turkish voters cast their ballots abroad.