Turkish news reports say police have launched a nationwide crackdown on union leaders and activists with alleged links to an outlawed Kurdish rebel group in the country's southeast.

The Anatolia news agency said more than 100 people were detained in simultaneous raids on at least 20 Turkish towns and cities. At least 10 of the arrests occurred in Istanbul, with others reported in Ankara, and Diyarbakir, the main city in Turkey's predominantly Kurdish southeast. The detainees included elected mayors, journalists, scholars and human-rights activists.

The reports say the detentions are related to the ongoing probe of the Kurdish Communities Union, a unit seen by authorities in Ankara as the political wing of the outlawed Kurdistan Workers Party, the PKK.

The outlawed party, founded in 1974, is considered a terrorist group by the European Union and the United States, which has supplied military hardware to Turkey to help fight the decades-long insurgency.

The PKK and its supporters are seeking an autonomous homeland in southeastern Turkey.