ISTANBUL, Turkey (CNN) -- Turkey's prime minister has promised to promote national unity and fight terrorism after his ruling Islamist party comfortably won parliamentary elections.
With nearly 100 percent of the vote counted, Recep Tayyip Erdogan's Justice and Development party, or AKP, claimed a new five-year mandate after it won 46.6 percent of the vote, Turkish electoral officials reported Monday.
Though its share of the vote was larger than it was in 2002, when it was voted into power, Turkey's system for apportioning parliamentary seats means it will hold 342 seats in the country's 550-seat parliament, down from the 363 it now holds.
The party's Islamic roots and its appeal to religious voters has unnerved many voters in a nation that has followed a strict code of secularism since it was founded in 1923.
Renewed fighting with Kurdish guerrillas along the mountainous southeastern border with Iraq has also led to widespread criticism from opposition parties.
But the country has been prosperous since Erdogan took office in 2003, promising to pursue pro-business policies and to push for Turkey's entry into the European Union. He urged his followers to accept the election results "with maturity." Watch as Turks digest results of election »
"The elections are over, but the test continues for us," he said. He added: "We practice unity politics, and we will continue doing that."
The secularist Republican People's Party (CHP), which dominated the Turkish republic from 1923 until 1950, won 20.8 percent of the vote and more than 100 seats in parliament.
The conservative National Movement Party, which has urged tough action against Kurdish guerrillas blamed for recent bombings in Ankara and other cities, won 14.3 percent and at least 70 seats in parliament.
The nationalists currently hold no seats in parliament, and their campaign appears to have drawn more support from Erdogan's ruling party than from the secular CHP.
In addition, the new parliament is expected to include 28 independent members -- most of them Kurdish.
Though a NATO ally, Turkey refused to participate in the U.S.-led invasion of Iraq. And it has been increasingly critical of the U.S.-backed Iraqi government's failure to crack down on Kurdish separatists it says are using Iraq's Kurdish territories as a staging area for attacks on Turkish soil.
Turkey has massed troops along its southeastern border, and top military officials have hinted that it was ready to launch strikes into Iraqi territory to deal with the separatists.
"In our struggle against separatist terrorists, we are determined to take every step at the right time," Erdogan said of the conflict with the Kurds, according to The Associated Press.
About 80 percent of Turkey's 42 million-plus eligible voters turned out Sunday, the government's electoral commission announced. The board is expected to certify the results within a week.
AKP supporters celebrated the party's office in Istanbul while in the capital Ankara hundreds whooped as they watched election results on a big TV screen set up outside party headquarters.
"We are very happy," university student Reyhan Aksoy told AP. "God willing, great days await us." Read how voters hailed Erdogan's victory a triumph for democracy
Erdogan called the elections in May, after opposition lawmakers blocked his choice of Foreign Minister Abdullah Gul to become the country's president.
The nomination sparked massive protests from Turks who feared the AKP would attempt to turn Turkey into an Islamic state.
It also elicited a warning from Turkey's powerful military -- which seized power from civilian governments three times and pushed out a forerunner of the AKP in the 1990s -- that it would step in if necessary to protect the republic's secular tradition.
European Commission President Jose Manuel Barroso congratulated Erdogan's victory.
"This comes at an important moment for the people of Turkey as the country moves forward with political and economic reforms," Barroso said in a statement.
The EU chief said Erdogan "has given his personal commitment to the sustained movement towards" the EU. E-mail to a friend
CNN's Talia Kayali contributed to this report.