NEW YORK — The Uzbek man taken into custody Monday and believed to be the gunman who carried out an attack at an upscale Istanbul nightclub, killing 39 people on New Year’s Day, has confessed, Turkish authorities said Tuesday.

The suspect, identified as Abdulkadir Masharipov, an Uzbek citizen born in 1983, received help in the attack, done “in the name of ISIS,’’ Vasip Sahin, the governor of Istanbul, said at a news conference.

“No one will get away with what they have done,’’ President Recep Tayyip Erdogan said from his office in Ankara, the capital.

Masharipov, whose arrest was confirmed by Prime Minister Binali Yildirim, was detained Monday night after police raided a residence in the Esenyurt district of Istanbul, which is home to a large number of migrants from former Soviet states in Central Asia.

He was arrested with four others, an Iraqi man and three women from countries including Egypt and another country on the African continent, the governor said.

Turkish officials said that the investigation into the New Year’s attack had uncovered a network of extremists from former Soviet states. And after the attack at Istanbul’s main international airport in June, which left scores dead, the three suicide bombers were identified by the Turkish authorities as citizens of Kyrgyzstan, Russia, and Uzbekistan.

Turkish news organizations released photos of the nightclub attack suspect, taken while he was in custody and showing bruises and blood on his face. But Sahin said that Masharipov had not opened fire when confronted by the police, and that officers had not used weapons while arresting him.

“He admitted his crime,’’ Sahin said, adding that the suspect had been trained in Afghanistan and speaks four languages.

Sahin said the interrogation, which he described as “very new,’’ was continuing but that more would be learned about who had helped Masharipov and how.

New York Times