Two explosions, one thought to have been a suicide bomb, killed 13 people outside a soccer stadium in Istanbul on Saturday, security sources said, in an attack that appeared to target police hours after a match between two of Turkey's top teams.
President Tayyip Erdogan described the blasts outside the Vodafone Arena, home to Istanbul's Besiktas soccer team, as a terrorist attack on police and civilians. He said the aim had been to cause the maximum number of casualties.
Interior Minister Suleyman Soylu said one of the explosions hit directly outside the stadium, while the suspected suicide bomber struck in the adjacent Macka park.
There was no immediate claim of responsibility. Islamic State, Kurdish and far-leftist militants have all carried out bomb attacks in recent years. The NATO member is part of the U.S.-led coalition fighting Islamic State in Syria, and is battling an insurgency by Kurdish militants in its southeast.
Three separate security sources said at least 13 people had been killed but there was no official confirmation of this. Soylu said he would make a statement on the death toll later.