A Turkish police officer stands guard near the site where a gunman opened fire in a crowded nightclub early on Jan. 1, 2017 in Istanbul.
A massive security operation unfolded to track down the fugitive assailant or assailants and any conspirators.
Emergency personnel carry away an injured woman at the site of the attack.
The Reina Club, where the attack took place, is one of Istanbul's best known nightspots, popular with local high society and foreigners. Some 600 people were thought to be inside when the gunman first shot dead a policeman and civilian at the door, then forced his way in and opened fire.
An armored police vehicle blocks a road leading to the nightclub.
People leave the scene of the attack.
A Turkish coast guard boat patrols in front of the Reina nightclub on the Bosphorous strait the morning after the attack.
The Reina nightclub is seen from the Bosphorus.
Some people jumped into the water to save themselves after the gunman began shooting at random just over an hour into the new year.
A young woman cries as she leaves flowers for the victims outside the nightclub on Jan. 1.