At least eight people were arrested for their suspected links to the PKK terror group in Turkey's megacity of Istanbul, police sources said Tuesday.

Anti-terror squads held simultaneous operations in seven districts of the city including Ataşehir, Kadıköy, and Üsküdar to apprehend the suspects, according to sources, who asked not to be named due to restrictions on speaking to the media.

The suspects are accused of spreading terror propaganda, giving financial support to PKK and joining some activities of the terror group.

Some organizational documents, as well as various weapons and munitions, were also seized in the raids, the sources added.

Another nine PKK-linked suspects were arrested in eastern Bitlis province on Tuesday, according to the Bitlis Governor's Office.

Anti-terror units of the Provincial Security Directorate detained nine suspects suspected of being a member of a terrorist organization and spreading terrorist propaganda.

Police also seized an unregistered automatic weapon, an unregistered pistol and magazine, an AK-47 cartridge, organizational documents and a large number of digital materials.

In its more than 30-year terror campaign against Turkey, the PKK -- listed as a terrorist organization by Turkey, the U.S. and the EU -- has been responsible for the deaths of some 40,000 people, including women, children, and infants.