The blast on Saturday sent panicked shoppers scurrying into side alleys off Istiklal Street, a long pedestrian avenue lined with international stores and foreign consulates, a few hundred meters from an area where police buses are often stationed, Reuters reported.
In a statement posted on its website, the Kurdistan Freedom Falcons claimed the responsibility for the attack, saying the attack in Istanbul was “revenge” for Turkish military operations against Kurdish rebels in the southeast.
According to Turkey’s Dogan news agency, ambulances rushed to the scene of the blast.
Reports say the attacker is among those killed.
Germany shut down its diplomatic missions and schools on Thursday, citing a specific threat.
The incident comes just days after a bombing attack, claimed by a Kurdish militant group, left about 35 people dead and over 127 others wounded in the capital, Ankara.