ISTANBUL (AP) — Hundreds gathered in Istanbul on Thursday to protest arrest and removal from office of a mayor from Turkey’s main opposition party over his alleged ties to a banned Kurdish militant group.

Ahmet Ozer, mayor of Istanbul’s Esenyurt district and member of the Republican People’s Party (CHP), was arrested by anti-terrorist police on Wednesday over his alleged ties to the Kurdistan Workers’ Party (PKK).

The Turkish government replaced Ozer with the deputy governor of Istanbul on Thursday, a move that CHP leader Ozgur Ozel and other politicians described as a “coup.”

The mayor’s arrest comes as Turkey debates a preliminary peace process to end a 40-year conflict between the PKK and the Turkish state that has left tens of thousands dead.

Protesters filled a square in Esenyurt after the government banned a gathering outside the municipal building. Some carried banners reading: “(We want) an elected mayor, not an appointed mayor” and calling for the resignation of President Recep Tayyip Erdogan’s government.

“In our opinion, this (government), acting against the law and violating the constitution, has committed a political coup. We will never accept it,” said Tulay Hatimogullari, the leader of the pro-Kurdish People’s Equality and Democracy Party, whose supporters joined the rally in solidarity.

Ozel, whose CHP made significant gains in local elections earlier this year, called for early elections.

Ozer, 64, is a former academic originally from Van in eastern Turkey. In March’s local elections, he was elected mayor of Esenyurt, a western suburb on the European side of Istanbul.

According to the state-run Anadolu Agency, Istanbul’s chief prosecutor’s office has found that Ozer has had contacts with PKK figures for more than a decade, according to an investigation.

Politicians and members of Turkey’s pro-Kurdish movement are regularly targeted for alleged links to the PKK, which is considered a terrorist organization by Turkey, the US and the European Union.

Lawmakers have been stripped of their parliamentary seats and mayors have been removed from office. Several lawmakers and thousands of party members have been jailed on terror-related charges since 2016.

Other opposition parties have been largely unscathed, but the CHP mayor of Istanbul, Ekrem Imamogluis currently appealing against a prison sentence and a political ban imposed by a court in December 2022 for “insulting” members of the Turkish election council in 2019.

Imamoglu accused Erdogan’s government of “plotting a dirty game” to wrest the Esenyurt municipality away from the opposition “by declaring Ozer a terrorist for fictitious reasons.”