Istanbul shooting site
Istanbul shooting siteReuters

Turkish authorities announced Wednesday that they have identified the gunman who killed 39 people in the New Year's day terror attack on an Istanbul nightclub. They have his fingerprints and picture and claim also to have his name.

Authorities have detained 20 alleged members of ISIS in connection with the attack, according to reports by the state-run Anadulo news agency. Police believe that the relatively easy escape of the attacker was due to his receiving help from the outside.

The suspects were arrested in the province of Izmir and were thought to have been living with the attacker in the city of Konya.

Anadolu also reported that police discovered numerous items of military hardware during their searches for the attacker, including night-vision equipment, a sniper scope, an ammunition belt and other items. Twenty children found at the suspects addresses were taken into temporary care.

Altogether, at least 36 people are being held in connection with the nightclub shooting, though the gunman who carried it out still remains at large.

ISIS claimed responsibility for the attack in a statement posted on Twitter, boasting of having carried out "the first major terrorist attack of 2017."