At least on police officer died and five people were severely wounded on Tuesday in a suicide bombing that targeted a police station in central Istanbul, Turkish media reported.
The attacker came running towards the police station in the central Sultangazi neighbourhood and blew himself up at the entrance, partially caving in the front door and the ceiling, said witnesses.
The rubble crushed several people, including police officers, inside the building. The wounded were taken to nearby hospitals and the toll was likely to rise, said an AFP photographer at the scene.
There was no immediate claim of responsilibity for the attack.
In May, a suicide bomb squad killed one policeman when they drove into a police station in the central city of Kayseri and opened gun fire before setting off a bomb.
That attack killed one officer instantly, left another in critical condition and wounded 16 civilians, including several children. The two assailants were also killed.
The outlawed Kurdistan Workers Party (PKK) said it had carried out the May attack.
Another suicide bombing took place last October in the eastern town of Bingol, where two people were killed when a woman blew herself up near the headquarters of the governing Justice and Development Party.
In November 2010 in Istanbul, a bomber blew himself up on the central Taksim square, wounding 32 people.