Censor.NET reports citing Reuters.
President Tayyip Erdogan described the blasts as a terrorist attack on police and civilians. He said the aim of the bombings, two hours after the end of a match attended by thousands of people, had been to cause the maximum number of casualties.
There was no immediate claim of responsibility. But the blasts came less than a week after Islamic State urged its supporters to target Turkey's "security, military, economic and media establishment".
Interior Minister Suleyman Soylu said the first explosion, which came around two hours after the end of the match between Besiktas and Bursaspor, was at an assembly point for riot police officers. The second came as police surrounded the suicide bomber in the nearby Macka park.
No victims among Ukrainians were reported by Consulate General of Ukraine in Istanbul.
The moment of explosion
First minutes after the explosion