Turkey election: Erdogan's AK Party seeks majority
Turks have voted in parliamentary polls for the second time in five months, as President Recep Tayyip Erdogan's AK Party tries to regain its majority.
Attempts to form a coalition government after elections in June failed.
The opposition says the vote is a chance to curb what it sees as Mr Erdogan's increasingly authoritarian tendencies.
Security is a key issue, amid clashes with Kurdish militants and attacks blamed on Islamic State (IS) militants.
Polls closed at 14:00 GMT. There is a ban on reporting results before 18:00 GMT, but authorities often lift it before that time.
Mr Erdogan has promised a return to stability if his party wins a majority.
"It is obvious in today's election how beneficial stability is for our nation and today our citizens will make their choice based on this," he said after casting his vote on Sunday in Istanbul. He has vowed to respect the result.
More on Turkey's crucial vote:
- Anxiety overshadows campaign
- Young voters want peace
- Kurdish city feels the pressure
- Erdogan faces future of power sharing
If the AK Party again fails to secure a single-party majority in the 550-seat parliament, it may be forced back to the negotiating table with either the country's main secularist CHP opposition or the nationalist MHP.
At June's election, Mr Erdogan sought a two-thirds majority to turn Turkey into a presidential republic, but his Islamist-rooted AK Party fell short.
The pro-Kurdish People's Democratic Party (HDP) upset his ambitions by crossing the 10% threshold, securing seats in parliament for the first time.
At the scene: Gavin Hewitt, BBC News, Istanbul
President Erdogan's motorcade drove into the courtyard of a school this morning to vote in a Turkey's second election this year. A small crowd of supporters clapped and cheered him. Some chanted 'stand firm. This nation is with you.'
Whilst he was voting his officials handed boxes of toy cars to the children. To his supporters he and the Justice and Development party he founded stand for stability in a period of increasing violence. Turkey has become a much more polarised society. His opponents accuse him of trampling on human rights and reducing press freedom.
This election will determine whether President Erdogan's party will regain its overall majority or whether it will be forced into a coalition. For European leaders - facing a migrant crisis - Turkey is the pivotal country if numbers of refugees are to be reduced.
In July, a ceasefire between the Turkish army and militants from the Kurdistan Workers Party (PKK) collapsed after a suicide bombing by suspected Islamic State (IS) militants near the border with Syria, which killed more than 30 Kurds.
Turkey then suffered its deadliest attack in its modern history when more than 100 people were killed after a peace rally attended by mainly left-wing demonstrators, including many HDP supporters, was targeted by two suicide bombers. The government said they were linked to IS.
The HDP scaled back its election campaign after the attack.
Critics have accused Mr Erdogan of renewing violence to curb support for the HDP - something the government denies.
The HDP's leader Selahattin Demirtas said on Saturday that some of his party's officials had been taken into custody, and questioned whether the election would be fair.
"We took the dictator down despite everything, and tomorrow we will show him how strong the power of the people is despite his impositions," he said.
In the run-up to the vote, the opposition felt increasingly wary, the BBC's Selin Girit reports.
Earlier this week, the offices of the opposition media group Koza-Ipek were raided by the police after the government's seizure of its assets.
Analysts say Sunday's vote is unlikely to resolve the deep divisions in Turkish society.