Turkish President Recep Tayyip Erdogan has claimed victory in a high-stakes election that could see him cement his power for another five years.
He also said his ruling AK Party and its alliance partner had secured a parliamentary majority.
However, the main opposition party said it was too early to call the result, adding it believed Erdogan could still fall short of the 50 percent needed to avoid a runoff next month.
State news agency Anadolu reported that Erdogan secured nearly 53 percent, with almost all ballots counted.
However, The Republican People's Party accused the outlet of manipulating results, saying half the ballot boxes had not yet been counted.
Sunday's vote brings in a powerful new executive presidency long sought by Erdogan and backed by a small majority of Turks in a 2017 referendum.
Critics argue the new Constitution will give too much power to one person.