ISTANBUL— A solid majority of Turkish voters approved sweeping changes to their military-era constitution — a referendum hailed by the government as a leap toward full democracy in line with its troubled bid to join the European Union.With 99 percent of the vote counted, 58 percent had cast ballots in favor of the constitutional amendments, state-run TRT television said. About 42 percent voted "no," heeding opposition claims that the reforms would shackle the independence of the courts.RELATED:'Turkey more influential globally than any of our members'The Sunday referendum on 26 amendments to a constitution crafted after a 1980 military coup had become a battleground between the Islamic-oriented government and traditional power elites — including many in the armed forces — who fear Turkey's secular principles are under threat.Voter turnout was 78 percent, and the result amounted to a vote of confidence in the ruling Justice and Development Party ahead of elections next year."We have crossed a historic threshold toward advanced democracy and the supremacy of law," Prime Minister Recep Tayyip Erdogan said at his party headquarters in Istanbul."The regime of tutelage in Turkey will now come to an end," he said. "The mentality will be so that those enthusiastic for military coups will see their enthusiasms stuck inside them." The amendments make the military more accountable to civilian courts and allow civil servants to go on strike. The opposition, however, believes a provision that would give parliament more say in appointing judges masks an attempt to control the courts, which have sparred with Erdogan's camp.The changes would also remove immunity from prosecution for the engineers of the 1980 coup. Kenan Evren, the military chief who seized power and became president, is 93 and ailing.Street clashes marred voting at several polling stations in provinces with large Kurdish populations. A Kurdish party had urged supporters to boycott the ballot, arguing that the proposed changes would not advance the rights of the ethnic minority.Since Saturday, police detained 138 people suspected of threatening people into boycotting the vote or casting their ballot in a certain way, Interior Minister Besir Atalay said.In a statement, the White House said President Obama called Erdogan just as the basketball final began to congratulate him for Turkey's role as tournament host, and "also acknowledged the vibrancy of Turkey's democracy as reflected in the turnout for the referendum that took place across Turkey today."German Foreign Minister Guido Westerwelle said the constitutional reform was critical to Turkey's bid for EU membership."This discussion in society, also about the concrete form of the balance of power in the state, is very much to be welcomed," Westerwelle said in a statement. "It certainly is not yet at an end."Devlet Bahceli, leader of Turkey's Nationalist Action Party, a hardline nationalist group, warned that the changes would weaken the state and embolden Kurdish rebels who seek autonomy. He said Turkey had entered "a dark era filled with critical risks and dangers." Erdogan brushed aside concerns, saying his party now wanted to seek consensus for an entirely new constitution.Many Turks are skeptical about their EU membership bid, partly because of European reluctance and a seemingly intractable dispute over the divided Mediterranean island of Cyprus. Yet in recent years, Turkey has grown confident on the international stage, seeking a role as mediator and improving ties with Iran and other neighbors while maintaining Western alliances.Many Kurdish politicians said they would not vote because the amendments do not specifically address discrimination toward the minority, which comprises up to 20 percent of the population. Kurdish rebels announced a suspension of attacks a month ago, but that unilateral cease-fire is due to expire on Sept. 20.