The Islamic State (IS) group has claimed responsibility for a gun attack on an Istanbul nightclub during New Year's celebrations which killed 39 people and left dozens injured.

Key points: Islamic State calls gunman a "heroic soldier"

Islamic State calls gunman a "heroic soldier" Eight people, not including gunman, have been detained

Eight people, not including gunman, have been detained 11 of the 39 victims were Turkish nationals, others mostly from Middle East

In a statement the group said "a heroic soldier" launched an attack on the "most famous nightclubs where the Christians celebrate their pagan feast".

Earlier Turkish media cited unnamed security sources saying they believed the gunman was likely to be an IS member from Uzbekistan or Kyrgyzstan.

Police had also established similarities with the high-casualty suicide bomb and gun attack at Istanbul's Ataturk Airport in June and were investigating whether the same IS cell could have carried out both attacks, the mainstream Hurriyet newspapers reported.

Turkey's state news agency said eight people, who did not include the gunman, had been taken into custody by anti-terrorism squads and were being questioned at Istanbul's main police headquarters.

The gunman, who is still at large, killed a policeman and another man outside the Reina club in the early hours of 2017 before entering and firing at an estimated 600 people partying inside with an automatic rifle.

Prime Minister Binali Yildirim said the attacker left a gun at the club and escaped by "taking advantage of the chaos" that ensued.

Some customers of the upscale club, which is often frequented by local celebrities, reportedly jumped into the waters of the Bosporus to escape the attack.

Sorry, this video has expired CCTV footage shows the attacker approaching the Reina nightclub

The Anadolu Agency said 38 of the 39 victims of the attack had been identified and, citing unidentified Turkish justice ministry officials, 11 of those killed were Turkish nationals and one was a Turkish-Belgium dual citizen.

The report said seven victims were from Saudi Arabia, three were from Lebanon and Iraq each, two were from Tunisia, India, Morocco and Jordan each. Kuwait, Canada, Israel, Syria and Russia each lost one citizen.

Anadolu says one victim remains unidentified.

Sixty-nine people were also wounded.

Relatives of the victims and embassy personnel were seen walking into an Istanbul morgue to take the bodies of the deceased.

Turkish officials have not released the names of those identified.

Turkish police officers stand guard outside the scene of the shooting. ( AP: Emrah Gurel )

Turkey and Russia strike IS sites in Syria, local media says

Turkey's state-run news agency said more than 100 IS targets in Syria had been hit by Turkey and Russia in separate operations, a day after the nightclub attack.

Citing the office of the Turkish Chief of General Staff, Anadolu Agency said Turkish jets struck eight IS group targets while tanks and artillery fired upon 103 targets near Al Bab, killing 22 extremists and destroying many structures.

Turkey sent troops into neighbouring northern Syria in August to clear a border area of IS militants and curb territorial advances by Syrian Kurdish forces.

Reuters/AP/ABC