A total of 31 people with suspected links to the PKK terror organization were detained Wednesday during simultaneous raids in Istanbul.

Counter-terrorism units of the Istanbul Police Department launched an operation to capture 43 previously-identified suspects, who are reportedly part of the PKK's political formation the Peoples' Democratic Congress (HDK).

As part of the investigation, 43 addresses located in 20 Istanbul districts were raided.

Pistols, hunting rifles, numerous bullets, documents and digital materials belonging to the terrorist organization were seized during the raids.

The detained suspects were reportedly planning terrorist attacks, local media said.

Work continues to capture the remaining 12 suspects, while the detained PKK suspects undergo necessary procedures at police headquarters.

Founded in 1978, the PKK has waged a decadeslong bloody campaign against Turkey.

The PKK, which is listed as a terrorist organization by Turkey, the U.S., and the EU, resumed its armed campaign in July 2015 after a brief reconciliation period.

Since that time, the PKK has been responsible for the deaths of some 1,200 security personnel and civilians, including women and children, while more than 4,000 security personnel and 2,000 civilians have been injured.