It was the first dismissal of a pro-Kurdish mayor since the local elections on March 31, in which the pro-Kurdish DEM party won control of 77 municipalities across Turkey.

"Mehmet Siddik Akis was dismissed from his functions as a temporary measure," the ministry said on social media platform X.

He was taken into custody "for belonging to a terrorist organisation", the ministry added.

Ali Celik has been appointed in Akis's place as the mayor of the southeastern town of Hakkari, the ministry said.

The vice-president of the DEM, Gulistan Kilic Kocyigit, told reporters the move was "an attack on the freedom to vote".

She urged a rally on Monday night in Istanbul to protest against the "illegality" of the mayor's removal.

Images shared on social media by a student activist association showed police later blocking access to a meeting point for the rally.

The rapporteur for Turkey in the European Parliament, Nacho Sanchez Amor, hit out at the move.

"And so it begins again," he wrote on X.

"Mehmet Siddik Akis, arrested & replaced by a trustee from the Gov.

"Blatant attack to democratic principles & total disregard to people's will."

In the March local elections, DEM -- accused by the Turkish government of links to outlawed Kurdish militants -- gained control of the local authorities in several large towns in Turkey's Kurdish-majority southeast, including the region's largest city, Diyarbakir.

More than 50 mayors elected in the southeast in the 2019 local elections on the HDP (now DEM) ticket have been stripped of office and replaced by state-appointed administrators for alleged ties to Kurdish militants.

The moves follow a 2016 coup attempt against President Recep Tayyip Erdogan's government, which prompted a massive crackdown on opponents of all stripes.