At least five others are said to have been wounded in the blast in the city of Izmir
Two suspected attackers have been killed by Turkish police after an explosion near a courthouse in the coastal city of Izmir.
Provincial governor Erol Ayyildiz told reporters: "A clash erupted after our police officers wanted to stop a vehicle at a police check point in front of Bayrakli courthouse.
"In this clash, terrorists detonated the car bomb while trying to escape."
Mr Ayyildiz said a police officer and a courthouse employee had been killed in the attack.
At least five others were reportedly injured, some of them critically.
Armed officers are said to be looking for a third suspect.
The attackers were armed with Kalashnikov rifles and grenades, officials said.
A rocket launcher, automatic rifle and eight hand grenades were seized by police.
Findings so far suggested that the PKK were behind the attack, Mr Ayyildiz said.
The governor said a second vehicle which is thought to have belonged to the attackers was destroyed in a controlled explosion.
Twenty suspected Islamic State militants were held in Izmir on Wednesday.
Turkish media reported that the raids were linked to the recent Istanbul nightclub attack.