The attack took place in the Sur neighbourhood of Diyarbakir province, where the Turkish army launched an intensive campaign last year against the outlawed Kurdistan Workers' Party (PKK).

The explosives detonated just as a police vehicle was passing by, the private NTV television reported.

It was not immediately clear who carried out the attack but the state-run Anadolu news agency pointed the finger of blame on "PKK terrorists."

Four of the nine wounded were also police officers, according to Anadolu.

Turkey has been on edge after a wave of attacks blamed on Kurdish militants and Islamic State jihadists.

The PKK -- designated as a terror organisation by Ankara, the United States and the European Union -- has been waging an insurgency against Turkey since 1984.