Turkish authorities detained 90 people on Tuesday over suspected links to the outlawed Kurdistan Workers Party (PKK) militant group, the Interior Ministry said.
The operation across eight provinces was carried out to prevent the activities of PKK members and the operation was ongoing, the ministry said in a statement.
The identity of those detained in Tuesday's operation was not immediately clear.
The pro-Kurdish Peoples' Democratic Party (HDP) had said on Sunday that 140 of its members had been detained over the previous three days, and that the detentions were politically motivated.
Turkey's government accuses the HDP of links to the PKK, which is designated a terrorist organization by the United States, Turkey and the European Union. The HDP denies such links.
The PKK has waged an insurgency against the Turkish state since 1984. Violence in the largely Kurdish southeast escalated after the collapse of a ceasefire in 2015.
Turkey has in recent months conducted regular strikes on PKK bases in northern Iraq, especially the insurgents' stronghold in the Qandil mountains, where Ankara has also threatened to carry out a ground offensive.