Turkish President Recep Tayyip Erdogan has won a new five-year term and will enjoy sweeping new powers after his victory in an election that global monitors said lacked "equal" conditions and his closest challenger said turned Turkey into "a one-man regime".
Election board chief Sadi Guven said officials were taking "administrative and judicial initiatives" over reported security problems as people voted in Sanliurfa, in the country's southeast, according to Turkey's state-run Anadolu news agency.
But he reckoned without Muharrem Ince, the presidential candidate of the secularist Republican People's Party (CHP), whose feisty performance at campaign rallies has galvanized Turkey's long-demoralized and divided opposition. Instead, Mr Erdogan claimed victory in the early hours of Monday morning with 53 per cent of the vote.
Not only did Erdogan win the election, he also won extensive new powers. "They have been generous in a way I haven't found in any other country I tried to travel to", he added.
A spokesman for Mr Erodgan's ruling Justice and Development Party (AKP), Mahir Unal, was quoted by CNN as dismissing the allegations, warning party leaders of "harsh outcomes" to any provocations.
Opposition parties and NGOs deployed up to half a million monitors at ballot boxes to ward against possible electoral fraud.
Analysts said Ince's emergence signalled for the first time that there could be a credible alternative to Erdogan, surpassing current CHP leader Kemal Kilicdaroglu.
The CHP's share of parliamentary votes, under the leadership of Kemal Kilicdaroglu, dropped by nearly 3 percentage points to 22.6 percent as compared to the results of the November 2015 elections.
In the opposition camp, the CHP had 23% and the pro-Kurdish Peoples' Democratic Party (HDP) 11% - above the threshold it needs to reach to enter parliament.
Five candidates ran against Mr Erdogan in the presidential race.
Observers praised the high turnout of around 87 percent, saying it proved the Turkish voters' commitment to democracy.
Sunday's vote makes him executive president, meaning he is both head of state and head of government, abolishing the role of prime minister.
"With the presidential system, Turkey is seriously raising the bar, rising above the level of contemporary civilizations".
Turkey's long-standing leader is standing over a long decline of the nation's currency.
The expected nationalistic discourse of AKP-MHP coalition in Parliament can also result in Turkey's cross-border moves against Kurdish militants in Syria and Iraq, and create a new fault line between Ankara and Washington over the latter's support for the Kurds of the region. A report by the Anadolu Agency said 10 foreigners - including French, German and Italian nationals - had been arrested over alleged attempts to "interfere" in the elections, citing Interior Ministry officials.
The elections took place under emergency rule, which Erdogan imposed two years ago after a botched military coup. This limits some freedoms and allows the government to bypass parliament with decrees.
Ince said he had garnered 15 million votes and would work to increase them to 30 million.
Turkish President Recep Tayyip Erdogan arrives to deliver a speech, June 24, 2018, in Istanbul, after initial results of Turkey's presidential and parliamentary elections.
The president's critics, including the European Union which Turkey still nominally aspires to join, say Erdogan has used the crackdown to stifle dissent.