At least 260 members of the Kurdistan Workers' Party (PKK) have been killed during Turkey’s week-long campaign against the group within the country and in northern Iraq, the state-run Anadolu Agency reported Saturday, citing unnamed security sources. At least 400 members of the PKK, which is considered a terrorist organization by the Turkish government, have also been injured.

Nurettin Demirtas, the brother of Selahattin Demirtas, who heads the pro-Kurdish Peoples’ Democratic Party (HDP), was also killed, Anadolu reported. The HDP has been, in the past, accused of having ties with the PKK, despite ideological differences.

The heaviest airstrikes on PKK targets were conducted Thursday when 80 Turkish aircraft hit more than 100 targets both inside and outside the country. In the operation, several shelters, underground caves and ammunition stores were reportedly destroyed.

The airstrikes against PKK, which began on July 24 -- ending a two-year ceasefire -- are still ongoing. On Saturday, at least six people were killed in a northern Iraqi village when a Turkish aircraft launched a pre-dawn raid as part of its two-pronged offensive against Kurdish militias and the Islamic State group.

However, while Turkey has carried out limited airstrikes against ISIS in northern Syria, it has shown more interest in targeting areas in northern Iraq held by the PKK. The Turkish military is not bombing ISIS-held areas in Syria’s Euphrates valley, where the Sunni militant group is fighting the Kurdish YPG militias -- the armed wing of Syria’s Kurdish Democratic Union Party, which is an affiliate of the PKK.

Meanwhile, the U.S. -- which counts Turkey as a key regional ally in its fight against ISIS -- is providing air support to the YPG fighters in Syria, even as the White House continues to maintain that the PKK is a “terrorist” organization.