Turkish special force police officers and ambulances are seen at the site of an armed attack January 1, 2017 in Istanbul
Istanbul (AFP) - Thirty-nine people were killed and dozens wounded Sunday when a gunman stormed a popular Istanbul nightclub and sprayed bullets at revellers celebrating the New Year.
Here is what we know about massacre claimed by Islamic State, the latest to rock Turkey after a bloody 2016.
- The attack -
The assailant shot dead a policeman and a civilian at the entrance to the Reina nightclub and then went on a shooting rampage inside, officials said.
The gunman then fired off four magazines containing a total of 120 bullets around the club, as terrified guests flung themselves into the freezing waters of the Bosphorus in panic.
He ranged through the kitchen and lower and upper levels of the clubs and reportedly shot victims in the head with his Kalashnikov.
On Monday, the Islamic State group said one of its "soldiers" had carried out the attack, which reportedly lasted seven minutes.
- The attacker -
Interior Minister Suleyman Soylu said the attacker escaped and was now the target of a major manhunt, expressing hope the suspect "would be captured soon".
Soylu said the assailant had changed clothes inside the club before escaping, leaving a weapon behind.
His name has not been revealed but images appear to confirm he is male.
Hurriyet daily said investigators believe the gunman may be from the Central Asian states of Kyrgyzstan or Uzbekistan.
The attacker may be linked to the same cell that in June carried out a triple suicide bombing and gun attack at Istanbul's Ataturk airport blamed on IS that left 47 people dead, the paper added.
- The venue -
The attack took place at the swanky Reina nightclub in the Ortakoy district on the banks of the Bosphorus on the European side of the city.
There were reportedly as many as 700 people celebrating the New Year which had chimed just over an hour before the shooting.
The club is one of Istanbul's most exclusive nightspots. It is notoriously hard to get past the bouncers who seek out only the best dressed.
Television pictures showed shellshocked revellers in party dress -- men in suits and women in cocktail dresses -- emerging dazed from the scene of the massacre.
- The victims -
Thirty-nine people were killed with another 65 being treated in hospital. Four of those injured were said to be in a serious condition.
There were 12 Turks killed and 27 foreigners.
The victims, including the 65 injured, came from all over the world including Iraq, France, Lebanon, India, Germany, Jordan, Russia, Canada, Saudi Arabia, Tunisia and elsewhere.
The youngest victim was Lian Nasser, 18, an Arab Israeli from the northern town of Tira who had come to the city with three friends and was having fun before the night descended into carnage.
- Terror in Turkey -
After a bloody 2016, the authorities were on their guard and at least 17,000 police officers were deployed in the city for the New Year festivities.
Turkey has endured bomb attacks at an airport, a suicide bombing at a wedding and an attack near a top football stadium last year.
The carnage has been blamed either on Kurdish militants or the Islamic State jihadist extremist group.
Last month, the Russian ambassador was shot dead at an Ankara art gallery by an off-duty policeman shouting "Allahu Akbar" (God is greatest) and "Don't forget Aleppo".
The Turkish army is waging a four-month incursion in Syria to oust the IS group and Kurdish militants from the border area.
Rebels from the outlawed Kurdistan Workers' Party (PKK) and what is considered its radical offshoot the Kurdistan Freedom Falcons (TAK) have claimed a spate of attacks since the collapse of a ceasefire in the summer of 2015.
- The reaction -
Turkish President Recep Tayyip Erdogan said in a statement that with such attacks, "they are working to destroy our country's morale and create chaos".
US National Security Council spokesman Ned Price said Washington condemned in the strongest terms the "horrific terrorist attack".
Russian President Vladimir Putin and German Chancellor Angela Merkel expressed their condolences to Erdogan.
"It's hard to imagine a crime more cynical than the killing of civilians during a New Year's celebration," Putin said.
Merkel said: "In Istanbul they committed an inhumane, sneaky attack on people who wanted to celebrate the turn of the year."