Watch: Erdogan and Kilicdaroglu cast votes in Turkish parliamentary and presidental elections

Turkish President Recep Tayyip Erdogan cast his vote on Sunday in a landmark parliamentary and presidential election that is expected to be tightly contested and could be the biggest challenge he has faced in his two decades in power.

Likewise, Kemal Kilicdaroglu, the joint candidate of a united opposition who is ahead of Erdogan in opinion polls, cast his vote in Ankara.

More than 64 million people, including 3.4 million overseas voters, are eligible to vote in the elections, which are taking place the year Turkey marks the centenary of the establishment of the republic.

If neither candidate receives more than 50% of the votes, the presidential race will be determined in a run-off on May 28.