Polls have closed in Turkey's parliamentary elections, with the country's prime minister and his Islamic-rooted party widely expected to secure a third straight term in power.

With about 50 million eligible voters, Sunday's election is pitting Recep Tayyip Erdogan's ruling Justice and Development Party, or AKP, against the Opposition Republican People's Party . Preliminary results are expected after 1800 GMT, but exit poll numbers usually emerge earlier.

The AKP is hoping to gain a crucial two-thirds majority in the 550-seat parliament, which would allow it to introduce a new constitution which it says would be more democratic. Supporters of Mr. Erdogan say a new constitution would enshrine the rights of minorities, such as the Kurds who have been fighting for autonomy in southeastern Turkey.

But critics of the Turkish leader say his government has become increasingly intolerant to criticism, and that his political goal is to create a more presidential-style government with him in control. They also accuse him of abusing his power and moving away from a secular state to a more conservative, Islamic form of government.

Though Sunday's vote has been peaceful, the Anatolia news agency says police detained 34 people in the mainly Kurdish southeast province of Batman for allegedly trying to coerce people into supporting Kurdish nationalists running as independents.

The Kurds had threatened earlier this year to boycott the elections after Turkey's main election board announced plans to ban seven Kurdish candidates from running. That decision was later reversed.

The outlawed Kurdistan Workers' Party, or PKK, has been fighting Turkey's military for an ethnic homeland since 1984. An estimated 40,000 people have died in the armed campaign.

Turkey, the United States and the European Union consider the PKK a terrorist group.