Suicide bomb kills five, wounds 36 in Istanbul shopping district

A suicide bomber killed himself and four others in a central Istanbul shopping and tourism district on Saturday, wounding at least 36 people in the fourth such attack in Turkey this year.

The blast sent panicked shoppers scurrying into side alleys off Istiklal Street, a long pedestrian avenue lined with international stores and foreign consulates, a few hundred meters from an area where police buses are often stationed.

The attack will raise further questions about NATO member Turkey's ability to protect itself against a spillover of violence from the war in neighboring Syria.

Turkey faces threats from Kurdish militants, whose insurgency has spread from the largely Kurdish southeast and who Ankara sees as closely linked to a Kurdish militia in Syria, and from Islamic State fighters, who have also recently targeted it.

Germany shut down its diplomatic missions and schools on Thursday, citing a specific threat. Meanwhile, U.S. and other European embassies had warned their citizens to be vigilant ahead of Newroz celebrations this weekend, a spring festival largely marked by Kurds which has turned violent in the past.

There was no immediate claim of responsibility for the bombing, which two senior officials said could have been carried out by the Kurdistan Workers Party (PKK), fighting for Kurdish autonomy in the southeast, or by an Islamic State militant.