Updated

Turkey's justice minister says police have detained 18 people in connection with a foiled attack at courthouse in the western city of Izmir that nevertheless killed a policeman and a courthouse employee.

The two assailants were also shot dead in Thursday's incident after they detonated an explosives-laden vehicle at a road block and engaged in a shootout with police. The attackers were armed with automatic rifles, rocket launchers and hand grenades.

Bekir Bozdag said Friday that authorities had "no doubt" that the outlawed Kurdistan Workers' Party, or PKK, "gave the orders" for the attack.

He was speaking at a memorial service for the slain police officer, who is believed to have thwarted a larger attack.

The attack was the latest in a string of assaults that have hit Turkey.