Attack is being blamed on so-called Islamic State, although no terror group has claimed responsibility
New Year's festivities at the Reina nightclub, an upmarket venue on the banks of the Bosphorus Strait in Istanbul, Turkey, came to an abrupt end at 1.30am local time (10.30pm UK time) when a gunman entered the club and opened fire, killing at least 39 people. At least 15 of those killed were tourists or other foreign nationals. The gunman is still at large.
Security footage shows the gunman arriving outside the club and killing two people - one a police officer - before going inside, where he opened fire indiscriminately. Some club-goers are said to have leapt into the water to avoid being shot. Some 70 shooting victims were taken to hospital and some are said to be in "very serious" condition, which means the death toll may still rise.
Early reports suggested the gunman was killed at the scene, but according to the Turkish interior minister that was incorrect, and a massive manhunt is now underway. Early reports that the attacker was wearing a Santa Claus outfit have also since been dismissed.
No terrorist group has claimed responsibility for the attack, but there the BBC reports that there were half a dozen large-scale attacks in Turkey in 2016, either by Kurdish militants or by supporters of so-called Islamic State. As Kurdish attacks have mostly targeted security forces, however, while IS attacks have focused on civilian targets, it's believed the latter group are behind the Reina atrocity.
A statement from Turkish president Recep Erdogan said in part: "We will retain our cool-headedness as a nation, standing more closely together, and we will never give ground to such dirty games. US president Barack Obama and Russian president Vladimir Putin have also issued statements condemning the attack.
**UPDATE 2/1/17: A statement issued by ISIS today has claimed responsibility for the attack in Istanbul. The gunman, who is believed to be of Central Asian origin, is still at large - he is believed to have escaped capture by posing as wounded civilian and mingling with survivors.