Turkish police have released photographs of the suspected attacker that opened fire at Istanbul’s Reina nightclub early on New Year’s Day, killing 39 people and wounding close to 70 others.

The publication of the images come as Turkey’s Deputy Prime Minister Numan Kurtulmus confirmed that eight people had been arrested by special forces in connection with the attack, which was claimed by the Islamic State (ISIS) on Monday.

A further four people were arrested in separate operations, the BBC reports. According to the BBC, none of the detained are thought to be the gunman.

“Information about the fingerprints and basic appearance of the terrorist have been found,” Kurtulmus told reporters. “The next step will be to try to identify him as quickly as we can.”

“We hope we will not only find the terrorist but also his connections and those people who gave him support inside and outside the club,” he added.

Read More: Istanbul Nightclub Shooting Heralds a New Year of Bloodshed in Turkey

Police gave no information on when or where the new images were taken. In addition, video footage has surfaced purporting to show the attacker pointing his gun as he approaches the club.

Turkish media also showed video purported to be of the suspect. It features a man in an undisclosed location handing over documents to an official. It is not clear when the video was recorded, and according to the BBC it could not be independently verified.

Police sources quoted by Turkish media said that the attacker may have been from Uzbekistan or Kyrgyzstan.

A statement from ISIS described him as “a heroic soldier” who carried out attacks against Turkey, which the terrorist group described as “the servant of the cross.”

[BBC]

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Write to Joseph Hincks at joseph.hincks@time.com.