Istanbul - A woman opened fire with a rifle at Taksim Square in central Istanbul on Friday, apparently aiming at police, Turkish broadcaster NTV reported.
The woman was not immediately apprehended and a search was ongoing.
Police secured the area by setting up barricades.
A female suicide bomber blew herself up earlier this month in the popular tourist area of Sultanahmet, killing one police officer.
Several days later, police defused two homemade bombs outside shopping centres in Turkey's largest city.