At least four people have been killed in a car bomb and gun assault on a courthouse in the Turkish city of Izmir, state media say.
Two attackers, a police officer and a court worker are being reported dead.
Officials blamed Kurdish militants for the attack. A third attacker is reportedly still being sought.
The attackers drove a car to the courthouse entrance, sparking an exchange with police and then detonating the car bomb.
Other of people were injured in the explosion, some critically.
Some of Turkey’s big cities have been targeted recently both by ISIS and by Kurdish militants.
Turkey launched a military operation in Syria last year to push back ISIS and Kurdish forces from the Turkish border.
Image source birgun.com
ISIS had said it was behind last weekend’s Istanbul club attack that left 39 people dead.
Izmir’s Governor Erol Ayyildiz the attackers were armed with Kalashnikov rifles and grenades.
Deputy PM Veysi Kaynak said that, judging by the weapons found following the raid, a much larger attack was being planned.
Images from the scene showed two cars ablaze. Erol Ayyildiz said that the second had been destroyed in a controlled explosion.
Reports of the number of people injured in the car bomb blast ranged from five to 11.
President Recep Tayyip Erdogan, speaking at the opening of a metro line in the capital, Ankara, said that Turkey was “under mutual attack by terrorist groups and they want Turkey to be brought to its knees”.
The Turkish president said: “They won’t be able to set people against each other. They couldn’t destroy our unity.”
No-one has yet said they carried out the Izmir attack but the governor said initial findings pointed to the involvement of Kurdish fighters from the outlawed Kurdistan Workers’ Party (PKK).
The PKK is fighting for an independent Kurdish state within Turkey.
It has carried out many attacks on Turkish security forces, particularly in the south-east.
A policeman has been killed and 17 people have been injured in a suspected suicide bomb attack outside a police station in the central Turkish province of Kayseri.
The two attackers, who also died, tried to ram a car into the building in the town of Pinarbasi, Interior Minister Idris Naim Sahin said.
A bomb in the vehicle went off shortly after clashes with security guards.
Sixteen civilians and another police officer were also injured, some seriously, reports said.
Some of the people who were hurt were the children of officers staying in nearby police lodgings, Idris Naim Sahin said.
The condition of the second police officer was unclear but Hurriyet newspaper said that he had been revived in hospital.
A policeman has been killed and 17 people have been injured in a suspected suicide bomb attack outside Pinarbasi police station in the central Turkish province of Kayseri
The interior minister described how the car had earlier sped through a police check point 90 km (55 miles) away in neighboring Kahramanmaras province, ignoring police calls to stop.
The attackers had driven into Pinarbasi after abandoning plans to strike another, unidentified target, reports said.
Television footage showed frantic scenes outside the police station, with fire engines and ambulances on site. Local media described an exchange of gunfire just before the bomb exploded.
“I heard a gun being fired and saw a policeman fall to the ground and suddenly there was an explosion. Shattered glass cut my hands, and I ran inside,” eyewitness Bahattin Ekinci said.
It is not clear if the device was detonated deliberately or as a result of the shooting.
Hasan Gumus, a civil servant who was working near the scene, said he and his colleagues had heard a “huge blast”.
“We saw a big cloud of smoke rising,” he told Reuters news agency.
Kayseri province is in the centre of Turkey, about 325 km from the capital, Ankara.
Nobody has so far said they carried out the bombing. But in an apparent reference to the separatist Kurdish PKK movement, Idris Naim Sahin said: “The crazy attacks of the terrorist organisation are continuing.”
Clashes between the PKK and the Turkish armed forces have increased in south-eastern Turkey over the past year, and the PKK has in the past carried out bombings in other parts of the country.
In September a powerful bomb in Ankara killed three people and wounded 15. That blast was blamed on the PKK.