One attacker with a long-range weapon was responsible for the carnage at Istanbul's Reina nightclub, the city governor has said.
"A terrorist with a long-range weapon… brutally and savagely carried out this incident by firing bullets on innocent people who were there solely to celebrate the New Year and have fun," Vasip Sahin told reporters, according to the BBC.
Initial reports said there were two or more attackers involved in the act of terrorism that has killed 35 and injured at least 40.
Witnesses say the gunman or gunmen were speaking Arabic. Sahin said the gunman killed a police officer and a civilian outside the club before firing on the crowd inside at around 1:45 a.m.
There may have been as many as 800 people inside, local media are reporting.
Revelers even jumped into the Bosphorus to escape the hail of bullets, according to social media reports.
Turkish police have now cordoned off the club, local media report.
According to Turkey's Hurriyet newspaper, security forces are also patrolling the Bosphorus Strait near the site of the attack.