A police officer has been stabbed to death by a suspected member of the Islamic State group, according to Turkish media.
The attacker was suspected of preparing to carry out a suicide bombing in Istanbul and had been taken to a police station for questioning.
It was then, at around 11pm local time, that the stabbing occurred, according to reports by the private Dogan news service.
The officer was taken away by ambulance but died in hospital.
The attacker was shot dead but questions remain as to how he had managed to keep a knife with him after he was arrested.