A gunman reportedly dressed in a Santa costume shot a police officer before storming the Reina club in the Ortakoy area of the city.
“Unfortunately, at least 35 of our citizens lost their lives. One was a police officer. Forty people are receiving treatment in hospitals,” Vasip Sahin told reporters at the scene of the elite nightclub on the city’s European side, describing the incident as a “terror attack”.
There were several hundred people in the club at the time. Many party-goers threw themselves into the Bosphorus in panic after the attack and efforts were underway to rescue them from the waters, NTV television said.
The whereabouts of the attacker was still unknown. Police special forces and explosives experts were searching the club, an NTV correspondent at the scene said.
TV footage showed armoured police vehicles surrounding the nightspot as ambulances rushed to the scene.
Police cordoned off the area about 2 miles away from the nightclub as multiple ambulances rushed to the scene.