Islamic State extremists have issued a call to war against Turkey, urging supporters in the country to rise up and conquer Istanbul, the country's largest city.
In a seven-minute video titled "A Message to Turkey," the group slams the country’s president, Recep Tayyib Erdogan, as a traitor "working day and night to hand over" the city it refers to as Constantinople to the "Crusaders."
The video, which was released Monday by Islamic State’s media office in the Syrian city of Raqqah, has raised alarm in neighboring Turkey, where many suspect the existence of sleeper cells in southern cities such as Gaziantep and Kilis.