Voting patterns showed Turkey deeply divided over the sweeping changes. Photograph: (AFP)
The 'Yes' campaign won 51.3% of the vote as the counting process has nearly ended, state media reported
In a historic vote Sunday, the people of Turkey sided with the President to usher in changes that will dramatically transform the country's political system and give president more powers.
In a closely watched referendum, the 'Yes' campaign was ahead with 51.34 per cent while the 'No' vote stood at 48.66 per cent at last count, state media said.
President Recep Tayyip Erdogan hailed Turkey for making a "historic decision" as he claimed victory in the referendum.
"Today... Turkey has taken a historic decision," Erdogan told reporters at his official Istanbul residence, the Huber Palace. "With the people, we have realised the most important reform in our history," he added.
Turkey's Prime Minister, Binali Yildirim, also declared victory in the historic referendum on expanding Erdogan's powers.
The opposition has questioned the legitimacy of the vote.
Erdogan also said he could hold a referendum on reinstating the death penalty, after claiming victory in the vote on a new constitution that gives him greater powers, AFP reported.
"If it (a parliament bill) comes in front of me, I will approve it. But if there isn't support (from the opposition in parliament)... then what shall we do? Then we could have another referendum for that," Erdogan said in a televised speech in Istanbul, referring to capital punishment, as supporters chanted for its reintroduction.
For the change to be implemented, the 'Yes' vote needed 50 per cent plus one vote.
The 'Yes' vote significantly enhances the powers of the president.
The voting happened under a state of emergency which has seen dramatic crackdown on dissenters after a failed putsch last year against Erdogan.
More than 55.3 million Turks were eligible to cast ballots on sweeping changes to the president's role. The change would grant Erdogan more powers than any leader since modern Turkey's founder Mustafa Kemal Ataturk and his successor Ismet Inonu.
The Constitutional reforms will strengthen the office of the president. He will be able to appoint top public officials including ministers directly.
The office of the prime minister, currently held by Binali Yildirim, a stauch Erdogan loyalist, will be scrapped.
The presidnet will be able to appoint one or more vice-presidents.
The judiciary will also see changes. Erdogan has accused the judiciary of being influenced by supporters of Fethullah Gulen, the US-based Islamic preacher who is blamed for last year's failed putsch.
(WION with inputs from AFP)