Media reports say that Turkish police on January 18 rounded up 27 people mostly from central Asia who they said were linked to an Uzbek gunman charged with killing 39 people in an Istanbul nightclub on New Year's eve.

Citing Turkey’s state-run Anadolu news agency, Associated Press reports that Turkish anti-terrorism squads had raided seven addresses in simultaneous operations in the northwestern city of Bursa, arresting 27 suspects from Kyrgyzstan, Uzbekistan, Tajikistan as well as from China's minority Muslim Uighur community. Fifteen of them were women.

Anadolu said police took 29 children into protective custody and seized 15 mobile phones set up with fake identity cards at one house that was connected to a Tajik national who police said was an Islamic State facilitator for foreign nationals.

Recall, the gunman, identified as 34-year-old Uzbek national Abdulkadir Masharipov, was caught late Monday in a police operation in Istanbul.

On January 1, the attacker shot his way into the Reina nightclub then opened fire with an automatic rifle, reloading his weapon half a dozen times and shooting the wounded as they lay on the ground.

Turks as well as visitors from several Arab nations, India and Canada were among those killed in the attack.

The Hurriyet newspaper said Masharipov, married with two children, was a dual Uzbek-Tajik national and spoke Russian, Arabic, Chinese and Turkish, as well as Uzbek.  He reportedly received two years training in Afghanistan and Pakistan and was believed to have entered Turkey via Iran.

His wife was detained last week in a raid in Maltepe, a coastal district on the Asian side of Istanbul, and their one-and-a-half year-old daughter was taken into care, Hurriyet said.

Hurriyet said Masharipov confessed to police and said he was instructed by IS leaders in Raqqa, Syria, initially to target Istanbul's famed Taksim square, but he changed his target at the last minute to avoid heavy security around the square.

Reuters says Masharipov was captured with an Iraqi man and three women from Africa, one of them from Egypt, in the Esenyurt district on Istanbul's western outskirts, about 30 kilometers from the Reina nightclub.  Two pistols, mobile phone SIM cards, two drones and $197,000 in cash were also seized.

Islamic State (IS) terrorist group claimed responsibility the day after the attack on the exclusive Reina nightclub, and said it was revenge for Turkey's military involvement in Syria.

IS has been blamed for at least six major attacks in Turkey since mid-2015, including an attack on a peace rally in October 2015 that killed more than 100 in Ankara.