A suicide bomber hit a busy tourist area in central Istanbul on Saturday, killing at least four people and wounding 20 others, Turkish media reported.
Police cordoned off Taksim square as helicopters flew overhead and multiple ambulances gathered at the scene.
Stunned shoppers ran away from the scene, some in tears. No group has claimed responsibility for the attack.
Car bomb explosion
The attack comes nearly a week after a car bomb ripped through a busy square in the capital of Ankara on March 13, killing at least 37 people, officials said. A Kurdish rebel group claimed responsibility.
The Kurdish Freedom Falcons, or TAK, is an offshoot of the Kurdish separatist group, PKK . It said on its website Thursday that its militants struck “in the heart of (the) fascist Turkish republic.”
The PKK, or Kurdistan Worker’s Party, seeks an independent state in Turkey. It has been in an armed struggle with Turkey for decades, and is a designated a terrorist organization.
Turkey has been carrying out operations in the predominantly Kurdish southeast. A ceasefire between the PKK and Turkey fell apart in July.
The terror group has accused Turkey of enabling ISIS, and assassinated two police officers. Turkey responded by bombing its positions in northern Iraq and targeting the southeast.