A special forces police officer takes security measures as he stands on top of a building where the portraits of Turkey's President Erdogan, Prime Minister Davutoglu and a Turkish flag are displayed in Istanbul

A special forces police officer takes security measures as he stands on top of a building where the portraits of Turkey's President Tayyip Erdogan, Prime Minister Ahmet Davutoglu and a Turkish flag are displayed in Istanbul, Turkey, June 3, 2015. Turkey holds a parliamentary election on June 7 that could reshape its political landscape. Erdogan hopes the result will help move Turkey towards a presidential system, while the pro-Kurdish opposition is aiming to enter parliament as a party for the first time. REUTERS/Murad Sezer