Two bombs exploded Sunday night in a crowded Istanbul shopping district, killing at least 17 people and wounding more than 100. No organization had yet claimed responsibility for the attack. Local newspapers suggested Monday morning that the police were focusing their investigations on the outlawed Kurdistan Workers Party (PKK). "It sounds like and it looks like the PKK," Gen. (ret.) Riza Kucukoglu, a researcher at ASAM, a strategic research institute in Ankara, told The Media Line. Kucukoglu further maintained that the PKK was most probably behind the attack, not only because of the method used, but also because of the pressure the organization faces in south-east Turkey and northern Iraq. Turkish aircraft have been bombing PKK bases in northern Iraq since mid-December 2007. The movement, which is listed as a terrorist organization by the United States and the European Union, used northern Iraq's mountainous regions as launching pad for attacks in Turkey. The most recent aerial strikes took place on Sunday, when warplanes targeted 12 PKK positions in the Iraqi Kandil Mountains. "The operations, carried out as part of the counterterrorism fight, will continue with determination both at home and abroad in accordance with military necessities," a Turkish military statement said. Also on Sunday, a group of three PKK operatives tried to attack a local police station in Bingol Province, south-east Turkey. In the ensuing gun-battle with security forces, one of the group members was killed while the two others were wounded, the Anatolia news agency reported. The PKK has conducted multiple terror attacks in Turkey since 1984. Nevertheless, the involvement of Al-Qa'ida in Sunday's attack cannot be ruled out, yet. Al-Qa'ida took responsibility for two bomb attacks in November 2003, which targeted the British consulate in Istanbul and the local headquarters of the British-owned HSBC bank. The attacks claimed dozens of lives, including that of the British Consul-General Roger Short. Earlier this month, Turkish policemen managed to thwart an attack against the United States' Consulate-General in Istanbul. Six people were killed, including three armed men and three policemen, during a shoot-out outside the consulate. The police announced it suspected the gunmen had ties to Al-Qa'ida, but said they had no proof so far. A third possibility is that an ultra-secular movement may have planted the devices in order to destabilize the current government, which is led by the Islamist AK Party.