A police officer was stabbed to death by a suspected member of the Islamic State group near a police station in Istanbul on Sunday, Turkish media said.
The attacker, who was suspected of preparing to carry out a suicide bombing, was shot dead after killing the policeman, the pro-government Anadolu news agency reported.
The assailant had already been arrested and was being transported to a police station when the stabbing occurred at around 11pm (2000 GMT), the private Dogan news service said, adding that the officer died from his wounds after leaving the scene in an ambulance.
It was not immediately clear how the man managed to keep a knife while being taken into custody.
Turkey was hit in 2016 by a succession of attacks that left hundreds dead in the bloodiest year of terror strikes in its history.
The attacks were blamed on IS militants who had taken swathes of territory in neighbouring Syria and Iraq as well as the outlawed Kurdistan Workers Party (PKK) who have battled the Turkish state in an insurgency lasting more than three decades.
The stabbing came just days after a Turkish police officer was killed in clashes between security forces and Kurdish PKK separatists in Turkey’s south-eastern Hakkari province.
Another police officer was also injured and rushed to hospital with non-life threatening injuries, a statement from Hakkari’s governor said.
Last year, an attack by a jihadist gunman on an elite nightclub in Istanbul just 75 minutes into New Year’s Day in 2017 left 39 people dead, mainly foreigners.
There has since been a lull in similar attacks, but tensions and high security remain in big cities.