Israeli officials say the number of Israelis killed in Saturday's suicide bomb attack in Istanbul has risen to three, among them two who also hold American citizenship.

The third victim was identified Sunday as Avraham Goldman, 69, from Herzliya. The two others are Sihma Damari, 60, from Dimona and Yonata Shor, 40, from Tel Aviv.

Five people including the suicide bomber were killed in an explosion that rocked Istanbul's pedestrian Istiklal Street, which is lined with shops and cafes and popular with tourists and locals alike. The area is also home to government offices and foreign missions.

There was no immediate claim of responsibility but suspicion has focused on the Islamic State group and Kurdish militants.

Turkey has been rocked by six suicide attacks in less than a year.