ISTANBUL — Turkey’s state-run news agency says police have detained five suspected Islamic State group militants believed to be linked to the deadly Istanbul nightclub attack.

Anadolu Agency says the operation was launched in the Aegean port city of Izmir on Wednesday. It says the operation in continuing.

The gunman who killed 39 people during New Year’s celebrations has not been publicly named and is still at large.

The IS group has claimed responsibility for the attack, which also wounded nearly 70 people.