A suicide bomber wounded 32 people in an attack targeting Turkish police in Istanbul’s main square yesterday, an area teaming with tourists and shoppers.

No organization has claimed responsibility, officials said, though the city has been targeted in the past by Kurdish separatist militants and al Qaeda, as well as militants from Turkey’s far-left.

Istanbul police chief Huseyin Capkin said a man had approached police stationed at the square before blowing himself up. TV footage appeared to show police firing warning shots and people fleeing in panic.

Taksim Square is a tourist and transport hub surrounded by restaurants, shops and hotels at the heart of Istanbul. The bomber struck near police buses parked close to a monument commemorating the founder of modern Turkey.