The IS statement accused Turkey of shedding the blood of Muslims through “its air strikes and mortar attacks” in Syria.
More details of the nightclub attack have been emerging. The gunman, who fired up to 180 bullets, arrived by taxi before rushing through the entrance with a long-barrelled gun he had taken from the boot of the car.
The attacker fired randomly at people in an assault lasting seven minutes, starting with a security guard and a travel agent near the entrance. Both were killed.
The gunman is reported to have removed his overcoat before fleeing during the chaos.
Turkish media reports quote police sources as saying he may have been from Uzbekistan or Kyrgyzstan.
A manhunt is under way, Interior Minister Suleyman Soylu confirmed. “We hope the attacker will be captured soon.”