Turkish news agencies say that members of a banned leftist group have taken a chief prosecutor hostage in his office inside a court house in Istanbul.

Private Dogan news agency says some shots were fired inside.

State-run Anadolu Agency and state television, TRT, identified the prosecutor as Mehmet Selim Kiraz. He is the prosecutor investigating the death of a teenager who was hit by a police gas canister fired during nationwide anti-government protests in 2013.

Dogan said special forces' police have entered the building, which has been been evacuated.

It was not clear how the assailants sneaked the arms in to the court house.