Turkish police officers say they have arrested nine people in connection with Sunday’s double bombing in a busy residential street in Istanbul. No further details have been released for publication, allowing analysts to continue pondering who was behind the deadly attacks. The working assumption is that the Kurdish separatist movement, the PKK, was behind the blasts, but the possible involvement of ultra-secularists has not been ruled out. Al-Qa’ida has also been mentioned as a possible perpetrator, however, the target and the method adopted did not bear the hallmarks of Al-Qa’ida. No one has claimed responsibility for the explosions that claimed 17 lives and wounded many more.