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.