A horrendous video has emerged online, showing an attacker armed with a rifle shooting directly at people at Istanbul’s Reina nightclub.

In CCTV footage, several people can be seen running and ducking for cover by an apparent entrance to a building in the street. A small dog can also be seen running away from the scene, as gunshots are visible right in the middle of the shot, reports Russia Today.

An attacker wearing a hat with a pompom then appears in the shot, his weapon in hand, aiming directly at his victims. He shoots right at them, and at least two people are seen falling to the ground.

WARNING!!! You may find the video disturbing as it contains scenes of violence and murder

The figure of the man cannot be clearly distinguished, and he wears a jacket over Santa Claus suit is caught on another shooting captured by a camera inside the club.

Separate surveillance footage from across the street was released by Turkey's Dogan news agency and depicts the opposite angle from the brutal recording that shows the gunman, who officials now believe to have been an operative of Isis, rushing into the nightclub.

The motive for the attack is not clear, but suspicion has fallen on the Islamic State group, already linked to at least two terror attacks in Turkey last year. The banned Kurdistan Workers' Party (PKK) has distanced itself from the killings, with the PKK's Murat Karayilan quoted as saying it would "never target innocent civilians", reports BBC News.

On Sunday, just over an hour into 2017, an unidentified gunman opened fire at partygoers at the Reina nightclub in Istanbul's popular Ortakoy neighborhood. The attack, which Turkish authorities are treating as a terrorist act, claimed at least 39 lives and injured almost 70. The gunman is reported to be still at large.