Turkish police have detained more than 30 people, including several mayors of Kurdish-majority towns, in an operation against alleged Kurdish separatists.
The raids, conducted in 11 provinces, targeted two outlawed organisations - the Kurdistan Workers' Party (PKK) and the Democratic Society Party (DTP).
The DTP was banned by Turkey's highest court two weeks ago. It was accused of links with PKK militants.
The PKK has been fighting for 25 years to create a separate Kurdish homeland.
The ban on the DTP sparked protests across south-east Turkey and was opposed by Prime Minister Recep Tayyip Erdogan, who had initiated a programme to improve Kurdish rights.
The DTP was the only Kurdish party represented in parliament. It was the latest of 10 pro-Kurdish parties to be closed down by the Turkish authorities.
The EU, which Turkey hopes to join, has expressed concern at the ruling.
Some 40,000 people have died since the PKK launched its armed campaign in the mainly Kurdish south-east. It is listed as a terrorist organisation by Turkey, the EU and the US.
Kurds make up about 20% of Turkey's population of more than 70 million.
The BBC's Jonathan Head in Istanbul says prosecutors are closing down the already limited opportunities for dialogue between the state and its largest minority.
Thursday's operation was the fifth this year. Fifty-two Kurdish activists are still being held after similar raids eight months ago - and all have been charged with membership of the PKK.
The dissolution of the DTP left the government without a negotiating partner for its peace plan, our correspondent says.
The party's MPs have now decided to retain their seats in parliament - but most of them have similar charges hanging over them. Only parliamentary immunity has protected them from arrest, Jonathan Head reports.