ISTANBUL, TURKEY—A man believed to be responsible for an Istanbul nightclub shooting on New Year’s Day, killing 39 people, was taken into custody on Monday, January 16. Turkish authorities have reported the suspect confessed to the shooting.

The New Year’s Day attack happened at a well-known nightclub in the Turkish capital of Istanbul. The suspect, Abdulgadir Masharipov, a 33, entered the nightclub and opened fire.

Masharipov, a Uzbek citizen, proclaimed he was attacking the nightclub “in the name of ISIS,” said Istanbul Governor Vasip Sahin during a news conference. Governor Sahin explained Masharipov received help from the Islamic State militant group that had claimed responsibility for the attack.

Masharipov was taken into custody Monday night after police raided a residence in the Esenyurt District that housed mostly migrants from the former Soviet states.

Sahin indicated that, along with Masharipov, one Iraqi man and three women were arrested. It was reported that the women were from different African countries. A pistol, ammunition, an air gun, two drones, and $197,000 were also found by officials at the home.

Turkish officials said their investigation, which reportedly involved around 2,000 officers, led them to a large number of extremists from the former Soviet states.

Officials reported that Marashipov is being held and questioned about any possible accomplices or leads, and if there any further attacks are planned against the country.