President Recep Tayyip Erdogan took an early lead on Sunday in Turkey's landmark election, state media reported, although the final outcome was likely to change substantially.
Erdogan was winning 53.2% of the vote with 34.4% of the ballots counted, while opposition leader Kemal Kilicdaroglu had 40.9% of the vote.
Most of the early ballots appeared to have been counted in heavily pro-Erdogan districts of Turkey's north and east.
A spokesman for Kilicdaroglu's Republican People's Party (CHP) said the opposition's internal count showed a "positive" result.
"We are seeing a positive picture, according to our data," CHP party spokesman Faik Oztrak said.
"We will start to give the numbers when the number of opened ballot boxes reaches a meaningful level."
Istanbul's opposition mayor Ekrem Imamoglu, who could be named vice president if Kilicdaroglu wins, urged the nation not to believe the figures released by Turkey's official Anadolu state news agency.
"We don't believe Anadolu at all," Imamoglu said.
Sunday's election is one of Turkey's most important of its post-Ottoman era, passing judgment on the country's longest-serving leader.
Most pre-election polls showed Kilicdaroglu enjoying a slight advantage and close to breaking the 50% threshold needed to avoid a May 28 runoff.
