( CNN ) -- Turkish Prime Minister Recep Tayyip Erdogan dominated debates leading up to Sunday 's local elections , even though he was n't on the ballot . Even before results were announced , a triumphant Erdogan spoke to cheering supporters from the balcony of the headquarters of his ruling Justice and Development Party , calling the vote a victory for democracy in Turkey . Erdogan said he delivered an `` Ottoman slap '' to opponents at the polls . He compared his opponents to medieval assassins , and he vowed to pursue them . Even though Erdogan was n't running for office , the closely watched municipal votes could show how much recent controversies and corruption probes are affecting support for him and his ruling party . CNN sister network CNN Turk reported that Erdogan 's party had taken a strong early lead in the vote count , but opposition sources contest that . Is Turkey approaching a breaking point ? Erdogan 's government faces a corruption probe , waves of street protests have wracked the country for nearly a year , and the country 's once-booming economy is slowing down . `` Despite all the undesired statements at rallies , today people will tell the truth and it will be beyond everything , '' Erdogan told journalists as he cast his vote earlier Sunday . `` People 's words will be decisive rather than those who spoke at rallies . For me , people will make the final call , and we respect people 's decision . '' As authorities counted votes in the nationwide municipal elections Sunday , rival parties claimed victory in the races for mayor in Turkey 's largest cities . The municipal vote is seen as a test of strength for Erdogan and the ruling Justice and Development Party , which has been in power since 2002 . Erdogan , who took office in 2003 , has been on the political defensive since December , when police detained dozens of people close to his government as part of a wide-ranging corruption probe . In subsequent weeks , the Prime Minister dismissed thousands of police commanders as well as the prosecutors leading the investigation . In early March , the death of a 15-year-old boy who had been hit in the head with a tear-gas canister during a demonstration last June sparked a new round of demonstrations . An Istanbul crowd chanted `` fascist government , Erdogan killer '' as Berkin Elvan 's coffin was carried through the streets of his family 's working-class Istanbul neighborhood . Erdogan fought back against critics who used social networks to attack him by vowing earlier this month to `` eradicate '' Twitter . The Twitter crackdown follows earlier threats by Erdogan to shut down Facebook and YouTube . Anonymous critics used the popular social networking sites to publish a series of audio recordings online that appear to be wiretaps of conversations of high-level officials , including Erdogan himself . The government has accused social media platforms of being used to spread false information and lies . The Prime Minister has called some recordings `` immorally edited material , '' including one in which a man who sounds like him purportedly instructs his son to hide tens of millions of dollars in cash from investigators . But he has also confirmed the authenticity of other wiretaps , including one in which he is heard telling the head of a major television news network to cut short the live broadcast of a rival politician 's speech in parliament . `` The electoral campaigns have been tough , '' Turkish President Abdullah Gul said as he voted . `` But I want Turkish people to remember that our state is strong . State institutions are also strong . The problems we face will be resolved within a legal framework . '' The leader of the main opposition Republican People 's Party , Kemal Kilicdaroglu , told reporters Sunday that he expected a `` good '' outcome . `` I have always told people , 'Listen to your conscience and vote accordingly . ' I hope they will do that , '' Kilicdaroglu said . `` I am happy , I cast my vote . Democracy in Turkey should be strengthened . It should be renewed . We will build it from the start . I trust my people . I trust their judgment . '' Brain drains while the heart stays : Is leaving Turkey an option ? Turkish economic mess : How did it get to this point ? CNN 's Mohammed Tawfeeq and Fionnuala Sweeney contributed to this report .
NEW : Turkey 's Prime Minister declares the vote a victory for democracy . Rival parties claim victory in municipal elections as authorities count votes . Prime Minister Erdogan 's government faces a wide - ranging corruption probe . Erdogan has tried to shut down Twitter , Facebook and YouTube as outlets for critics .