Turkish President Recep Tayyip Erdogan cast his ballot in Istanbul at 13:55 local time.
"Turkey is experiencing a democratic revolution with this election," President Erdogan said as he cast his vote, according to Anadolu News Agency, which also cited the president as saying that "with the new governing system, Turkey will be able to reach the level of contemporary civilizations."
Turkey's opposition leaders, Kemal Kilicdaroglu and Muharrem Ince, also cast their votes at 11:47 a.m. local time.
Anadolu has reported "some complaints of doubtful votes and disputes near ballot boxes", adding that the voting process has gone "smoothly", nonetheless.
The agency also reported the arrest of ten foreigners with French, German and Italian nationalities, who "did not have accreditation from Turkish government", and were trying to interfere in Turkish elections. Turkish officials said that legal proceedings have started against these foreigners.
The voting process for 56.3 million registered citizens began at 8 a.m. and ended at 5 p.m. local time at 180,065 ballot boxes in all 81 provinces of Turkey.
The voting will elect 600 lawmakers and the country’s first president with broad executive powers.
Some 1.65 million registered citizens will be casting their first votes in the snap election, which will herald a switch to a new powerful executive presidency narrowly approved in a controversial referendum last year, marred by allegations of fraud.
For the first time, the presidential and parliamentary ballots will be placed in a single envelope.
While two broad electoral alliances are entering the parliamentary elections, six names are running for the presidential office.
President Recep Tayyip Erdoğan is up for the seat from the “People’s Alliance,” racing on behalf of the ruling Justice and Development Party (AKP) and the Nationalist Movement Party (MHP).
Muharrem İnce is running from the main opposition Republican People’s Party (CHP) and jailed Selahattin Demirtaş is running from the Kurdish issue-focused Peoples’ Democratic Party (HDP).
İYİ (Good) Party leader Meral Akşener, Felicity Party (SP) leader Temel Karamollaoğlu and Patriotic Party (VP) leader Doğu Perinçek are also running for the post after collecting 100,000 signatures from citizens to be nominated.
Some 415 observers from eight international organizations have been deployed to watch Turkey’s presidential and parliamentary elections on Sunday.
The foreign observers -- including parliamentarians from several countries -- have completed their accreditation with Turkey’s Supreme Election Council.
The Organization for Security and Cooperation in Europe (OSCE) has sent 234 observers, while the Parliamentary Assembly of the Organization for Security and Cooperation in Europe (OSCEPA) sent 72, the Parliamentary Assembly of the Council of Europe (PACE) deployed 35, and the Parliamentary Assembly of the Mediterranean (PAM) sent 10 observers.
There are also five observers from the Parliamentary Assembly of the Black Sea Economic Cooperation (PABSEC), 15 from the Parliamentary Assembly of Turkic-Speaking Countries (TURKPA), 21 from the Turkic-Speaking Countries Cooperation Council (Turkish Council), and 23 from the Shanghai Cooperation Organization (SCO).
They are tasked with monitoring if the elections are carried out in a fair, free, and transparent manner.
The observers will be able to watch voting and ballot counting so long as they do not interfere with these procedures.
The election monitors will also prepare reports on whether international standards are followed.