An explosion at a major tourist shopping area in the Turkish city of Istanbul has injured a number of people, Turkish media say. Pictures showed people running away in panic. Some reports say it was a suicide bomb attack that killed at least another person. The area - Istiklal Street - is reportedly crowded at weekends. Last Sunday, an attack in the capital, Ankara, claimed by Kurdish militant group TAK, killed 37 people. The TAK, an offshoot of the banned Kurdistan Workers' Party (PKK), said that was in revenge for Turkish military operations in the mainly Kurdish south-east.