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 was being taken to a police station.
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 later.
The attacker was shot dead but questions remain as to how he had managed to have a knife with him after he was arrested.