Polls have closed in the Turkish elections - where voters are deciding whether to grant President Recep Tayyip Erdogan a second five-year term according to "BBC".
He has faced a tough battle with Muharrem Ince، a centre-left candidate who has energised the opposition.
Casting his own vote، the president claimed there had been a high turnout. First results are due later on Sunday.
If Mr Erdogan wins، he will adopt major new powers that critics say will weaken democratic rule.
He is hoping to get more than 50% of the vote in this ballot to avoid going to a second round.
As well as the presidency، voters are also choosing members of parliament.
Turkey remains under a state of emergency imposed in the aftermath of a failed coup in July 2016.
These elections were originally scheduled for November 2019 but were brought forward by Mr Erdogan.
"Turkey is going through a democratic revolution with this election،" the president told reporters after he voted in Istanbul.
Meanwhile Turkey's electoral commission said it would look into reports of ballot-stuffing and intimidation of observers in the southern Urfa province، which borders Syria.
Mr Ince، whose fiery campaigning has revitalised Turkey's demoralised opposition، promised to push back what he characterised as a slide into authoritarian rule under Mr Erdogan.
"If Erdogan wins، your phones will continue to be listened to... Fear will continue to reign،" he told at least a million people gathered in Istanbul. "If Ince wins، the courts will be independent."
Mr Ince also said that if elected، he would lift Turkey's state of emergency within 48 hours. Emergency rule allows the government to bypass parliament.
At his own rally، President Erdogan - who was prime minister for 11 years before becoming president in 2014 - used a violent metaphor to summarise his hoped-for result، asking supporters، "Are we going to give them an Ottoman slap [a technique for knocking someone out] tomorrow?"
He accused Mr Ince - a former teacher and MP of 16 years - of lacking the skills to lead.
"It's one thing to be a physics teacher، it's another thing to run a country،" Mr Erdogan said. "Being president needs experience."