ANKARA, Turkey (AP) — A Turkish court on Thursday sentenced several pro-Kurdish politicians to between nine and 42 years in prison over deadly riots in 2014 by Kurds angered by what they perceived to be government inaction against Islamic State group militants who had besieged the Syrian border town of Kobani.

The three days of clashes that broke out in October 2014 resulted in 37 deaths and left hundreds of others — police and civilians — injured. The protests were called by leaders of Turkey’s pro-Kurdish People’s Democratic Party, or HDP, who were frustrated by what they considered to be Turkish support for IS militants.

A total of 108 people were charged with various crimes, including the killings of the 37 victims and crimes against the integrity of the state. The defendants include HDP’s imprisoned former leaders, Selahattin Demirtas and Figen Yuksekdag, who were accused of organizing the protests and inciting the violence.

Critics decried the trial as politically motivated and part of a wider government crackdown on the pro-Kurdish party.

Of the defendants, 18 were jailed, 18 others were freed pending the verdict and 72 remain at large.

The court in Ankara convicted Demirtas - who has run for president twice - of a total of 47 charges and sentenced him to 42 years in prison, state broadcaster TRT reported. Yuksekdag was sentenced to 30 years in prison for attempts to challenge the unity of the state, of inciting criminal acts and of engaging in propaganda on behalf of a terror organization.

Twelve defendants were acquitted of all charges. Defendants still at large would be tried at a later date.

The politicians are expected to appeal the verdicts.

The hearing took place in a tense atmosphere with lawyers banging on desks and leaving the courtroom to protest the verdicts, Cumhuriyet newspaper reported.

The pro-Kurdish movement’s current co-leader, Tuncer Bakırhan, described the verdicts as a “black stain” on the Turkish justice system.

“The Selahattins, the Figens and others who were prosecuted in this Kobani conspiracy trial have been acquitted in the hearts and minds of the Kurds, the Turks, the workers, the women and the young,” he said.

In anticipation of protests condemning the sentences, authorities imposed a four-day ban on demonstrations in the predominantly Kurdish provinces of Diyarbakir, Siirt, Tunceli and Batman.

The government accused the HDP of links to the outlawed Kurdistan Workers’ Party, or PKK, which is considered a terror organization by Turkey, the U.S. and the European Union. The group has led an armed insurgency against the Turkish state since 1984 and the conflict has killed tens of thousands of people.

Government officials accused the HDP leaders of taking instructions from the PKK to stage the riots.

The government has frequently cracked down on the pro-Kurdish political movement by stripping legislators of their parliamentary seats and removing elected mayors from office. Several HDP lawmakers have been jailed alongside Demirtas and Yuksekdag, on terror-related charges.

The party has since changed its name to the Peoples’ Equality and Democracy Party, or DEM, and is the third-largest grouping in Turkey’s parliament.