DIYARBAKIR, Turkey — When Kurdish officials here in Diyarbakir, the biggest Kurdish city in the world, say they’ve been “unavoidably detained,” it is not just an excuse for lateness.

Even before I arrived, the co-mayors, Gultan Kisanak and Firat Anli, were jailed on terrorism charges that rights groups say are trumped up. Interviews in prison are not possible because, officially, foreign journalists are barred from the city.

Ahmet Turk, 74, a Kurd despite his name and the venerable mayor of another Kurdish city, Mardin, was out of jail at the moment. But his press officer, Enver Ete, said that it would be hard to arrange an interview: “We can’t give a time since so many people are getting arrested we can’t foresee what will happen.”

Kamuran Yuksek, a Kurdish politician, was on the phone with a reporter when he was detained briefly — just after being released from five months in prison.