ISTANBUL, Jan. 5 (Xinhua) -- An explosion in Turkey's western city of Izmir wounded 11 people on Thursday, local media reported.

CNNTurk reported that two "terrorists" have been killed by security forces after the blast, believed to be caused by a car bomb, outside a courthouse.

Police are now after a third attacker, CNNTurk said.

Dogan news agency said police officers were among the 11 injured in the blast.

The explosion in Izmir Thursday followed an attack early Sunday on an Istanbul nightclub that left at least 39 dead.

The Islamic State group has claimed responsibility for the nightclub carnage. The gunman remains at large.