BERMAN: A deadly terror attack this morning at one of the great tourist hubs. A suicide bomber killed at least 10 people in a popular and heavily guarded square in Istanbul. Turkish officials say the attacker was with ISIS and came into the country from Syria.</s>BOLDUAN: Many of the victims, they were German tourists. Germany is urging its citizens to avoid tourist attractions and large gatherings in Turkey. CNN's Arwa Damon is there. She's at the site of the blast. Arwa, what more are you learning?</s>ARWA DAMON, CNN SENIOR INTERNATIONAL CORRESPONDENT: We're just outside the police cordon here. The attack happened around 10:15, 10:20 this the morning. That Bent off in the heart, the center of Turkey's historic -- Istanbul's historic tourist districts, one of the main places you would visit if you were coming here as a tourist. According to authorities, this individual was of Syrian other begin origin, was a member of ISIS. Not someone Turkish officials were tracking. Someone we're being told recently crossed from Syria into Turkey.
Germans Killed in Istanbul Terror Attack.