Istanbul, May 15 : Turkish President Recep Tayyip Erdogan cast his vote for twin presidential and parliamentary elections in a school in Istanbul, the country's largest city. Erdogan arrived at the school in the Uskudar district on Istanbul's Asian side with his wife, Emine Erdogan, at 11:40 a.m. local time (0840 GMT) on Sunday, Xinhua news agency reported. "According to the information I received from the Interior Minister, the voting process is going on without any problems, without incidents," the President told reporters after casting his ballot, adding voting in Turkey's earthquake zones is also going on without any difficulty. "The fact that all our voters cast their votes until 5 p.m. without any concern is very important in demonstrating the strength of Turkish democracy," Erdogan stressed. The presidential election is expected as a tight race between two candidates, incumbent President Recep Tayyip Erdogan and Kemal Kilicdaroglu, leader of the Centre-Left Republican People's Party. The third candidate Sinan Ogan is appealing for nationalist votes and the fourth presidential contender Muharrem Ince withdrew from the race on Thursday. Kilicdaroglu, 74, also cast his vote on Sunday for the elections. Erdogan, 69, founder and leader of the ruling Justice and Development Party, has been leading the country since 2014 as the 12th president. He served as Turkey's Prime Minister from 2003 to 2014 and as Mayor of Istanbul from 1994 to 1998. /IANS