A suspected suicide bomber wounded 32 people in the centre of Turkey's biggest city in an attack targeting police.
Fifteen policemen and 17 civilians were wounded in the attack in Taksim Square, Istanbul, local governor Huseyin Avni Mutlu said.
No organisation has claimed responsibility.
CNN-Turk said a second bomb was found close to the dead bomber, but state-run Anatolian news agency said parts of a bomb were found and it was unclear if it was part of the exploded bomb or a second device.
Taksim square is a major tourist attraction and transport hub, surrounded by restaurants, shops and hotels, and at the heart of modern Istanbul.
Istanbul has been targeted before by Kurdistan Workers Party (PKK) rebels, but the separatist group extended a unilateral ceasefire last month.
Other groups, including Al-Qaeda, have also attacked the city. Al- Qaeda suicide bombers were behind a series of bomb attacks in Istanbul in November 2003 that killed 57 people and wounded hundreds.
