Istanbul police on Thursday have found 4.5 kilograms of handmade bomb placed in a pressure cooker, reportedly prepared by the PKK terrorist organization.The police carried out raids on a house in the city's Başakşehir district, where they found a map with markings on specific locations. The police went to the designated location where they found a 4.5 kg handmade bomb placed in a pressure cooker, said to have been prepared by the PKK to be used in a "provocative action."The Turkish government has intensified its counterterror operations following the recent attacks carried out by the PKK, which is recognized as a terrorist organization by the U.S., the EU and Turkey.Formed in 1978, the terrorist group has been fighting the Turkish government for an independent state until the early 2000's. The group then shifted its goal to autonomy in predominately Kurdish inhabited regions of Turkey.In a separate incident, it was alleged that a DHKP-C member who was detained Thursday in front of the Istanbul police headquarters on Vatan Street was planning to bomb the headquarters. The Revolutionary People's Liberation Party-Front (DHKP-C) is an offshoot of a Marxist-Leninist movement that was established in the 1970s. The DHKP-C was founded in the 1990s after it splintered from a larger group of far-left organizations responsible for a string of attacks that include the assassination of two politicians in 1980, several intelligence officials and prominent businessman Özdemir Sabancı.