Turkish authorities said Wednesday that they have established the identity of the gunman who killed 39 people at a popular nightclub in Istanbul early Sunday. Foreign Minister Mevlut Cavusoglu announced the development in a televised interview with the state-run Anadolu news agency, but did not reveal the name of the attacker.

The gunman, who fled after the attack, is still at large and a massive manhunt is underway. According to reports, the attacker spoke Arabic as he opened fire at the Reina club in the early hours of New Year's Day. At least 600 people were at the venue when the gunman stormed in after killing a policeman and a civilian outside the club.

Local media reported that some 20 people have been detained as a part of the investigation into the shooting.

On Monday, the Islamic State group claimed responsibility of the attack saying that a "soldier of the caliphate" had carried out the shooting in response to Turkish military operations against ISIS in northern Syria.

On Tuesday, Turkish state media released a video of the suspected perpetrator of the deadly terrorist attack. The clip shows the alleged gunman filming himself with a cellphone at Istanbul's Taksim square. It is unclear if the video was filmed before or after the massacre.

Meanwhile, Kyrgyzstan ruled out a suspect named in media reports in connection with the attack after an image of a Kyrgyz passport purportedly belonging to the suspect circulated on social media.

So far, there have been several conflicting reports about the identity of the gunman. On Monday, local media reported that the attacker was believed to be from a Central Asian nation and may have been part of the same cell that targeted Istanbul's Ataturk Airport in June 2016. On Tuesday, Haber Turk newspaper reported, citing sources, that the attacker is believed to be a member of China's Muslim Uighur minority.

Some reports claimed that police gathered the details of the suspect from calls he made on the mobile phone of the taxi driver who took him to the nightclub.