A suicide bomber believed linked to the Islamic State in Syria set off a powerful blast Tuesday in one of Istanbul's most popular tourist districts, officials said, killing at least 10 people and injuring 15 with reports citing Germans as among the main casualties.
The attack in the shadow of the famous Blue Mosque was a further sign of the country's deepening instability in a region wracked by war and the expanding reach of groups such as the Islamic State, which uses Turkey as a critical lifeline for recruits, supplies and oil smuggling.
Turkey's prime minister, Ahmet Davutoglu, described the bomber as a member of the Islamic State, but gave no other immediate details.
