That deadly attack had come a day after the authorities arrested a man carrying explosives in a backpack outside an underground station in central Istanbul.
Private news agency Cihan said the cause of Wednesday's blast on the European side of the city was still not known.
Bombings are not uncommon in Turkey, where Kurdish separatists, al-Qaeda and left-wing fighters have all been blamed for attacks.
No one claimed responsibility for last week's attack but local officials blamed Kurdish separatists.
Tensions are running especially high because Turkey has been carrying out cross-border military strikes in northern Iraq aimed at the separatist Kurdistan Workers party.