Istanbul attacker 'fought for ISIS in Syria'

The gunman who killed 39 people at an Istanbul nightclub had fought in Syria for the Islamic State, a report said on Tuesday, as Turkish authorities intensified their hunt for the attacker.

The Hurriyet daily said that the attacker - who has yet to be formally identified and remains on the run - showed signs of being well trained in the use of arms. According to Hurriyet columnist Abdulkadir Selvi, he had been trained in street fighting in residential areas in Syria and used these techniques in the attack, shooting from the hip rather than as a sniper.

The attacker had been "specially selected" to carry out the shooting, he said.

Police released pictures of the suspect who went on the rampage at the plush Reina nightclub on New Year's night, spraying some 120 bullets at terrified guests before slipping away into the night.

The release of the image on Monday came as Deputy Prime Minister Numan Kurtulmus said that the country's state of emergency - already in place at the time of the attack - would be extended for as long as needed.

The Islamic State group on Monday claimed the massacre, the first time it has clearly stated being behind a major attack in Turkey.

The government said Monday that eight people had been detained but media reports said the number had increased to 12 after new detentions in the Anatolian city of Konya.

The Dogan news agency said they included a woman suspected of being his wife but gave no further details.

Kurtulmus said authorities were close to identifying the gunman after obtaining his fingerprints and a description of his appearance.

"Information about the fingerprints and basic appearance of the terrorist have been found. In the process after this, work to identify him swiftly will be carried out," Kurtulmus told a news conference.

He added that it was clear that Turkey's military incursion into Syria, launched in August, had annoyed armed groups and those behind them, but said the offensive would continue until all threats to Turkey were removed.

Turkey sent tanks and special forces into Syria just over four months ago to push back ISIS fighters from its border and prevent Kurdish fighters from taking ground in their wake.