Turkey's ruling party won a landslide victory in Sunday's parliamentary elections, but fell short of the two-thirds majority needed to amend the constitution.

With nearly all the ballots counted, state-run television is giving Prime Minister Recep Tayyip Erdogan's Justice and Development Party 50 percent of the vote. The main opposition Republican People's Party has 26 percent, while the Nationalist Action Party won 13 percent.

Mr. Erdogan calls the election results a victory for democracy, stability, and peace. But his party will wind up about 40 seats short of a two-thirds majority, meaning he would have to turn to at least one opposition party for support to revise the constitution.

The prime minister has promised to amend the constitution, written in 1982 when Turkey was under military rule.

It is unclear what changes he plans to make. But political opponents have said they believe Mr. Erdogan is becoming more autocratic, less tolerant of the opposition, and moving Turkey away from a secular state to a more Islamic-style government.

His backers say the amended constitution would guarantee more rights for minorities, including Kurds.

The Kurds had threatened to boycott Sunday's vote 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. The fighting has killed about 40,000 people. Turkey, the United States and the European Union consider the PKK a terrorist group.

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