Police in Istanbul are hunting for a gunman who opened fire at a well-known nightclub, killing at least 39 people.

The attack happened at Reina nightclub early on Sunday, as hundreds of revellers marked the new year.

Officials say some 15 foreigners were killed, including citizens from Israel, France, Tunisia, Lebanon, India, Belgium, Jordan and Saudi Arabia.

The attacker left his gun before “taking advantage of the chaos” and fleeing the scene, Turkey’s PM said.

Binali Yildirim also confirmed the gunman was not dressed as Santa Claus, contradicting earlier reports.