By Cihan Demirci

EDIRNE, Turkey

The co-chair of Turkey's opposition Peoples’ Democratic Party (HDP), Selahattin Demirtas, was put behind bars late Friday after being remanded in custody in a terror investigation.

Demirtas was taken to the western Edirne province from Diyarbakir in the southeast where he was remanded after failing to answer a summons linked to a counter-terrorism investigation, according to judicial sources who spoke on condition of anonymity.

He is currently being held at the Edirne F-Type prison.

Prosecutors ordered the arrest of party co-chairs Figen Yuksekdag and Demirtas, along with 13 other HDP deputies, according to an Interior Ministry statement.

The detentions were carried out in Ankara, Diyarbakir, Hakkari, Van, Sirnak and Bingol provinces.

In addition to the co-chairs, the party's parliamentary group leader, Idris Baluken, Diyarbakır Deputy Nursel Aydogan, Sirnak Deputies Leyla Birlik and Ferhat Encu, Mardin Deputy Gulser Yildirim, and Hakkari Deputies Abdullah Zeydan and Selma Irmak also were remanded in custody.

Diyarbakir Deputies Ziya Pir and Imam Tascier, and Ankara Deputy Sirri Sureyya Onder were released under judicial control, while Sirnak Deputy Faysal Sariyildiz and Van Deputy Tugba Hezer Ozturk were said to be abroad.

An arrest warrant for Hakkari Deputy Nihat Akdogan is also out.

The lawmakers face prosecution under anti-terrorism laws after their parliamentary immunity was lifted earlier this year.

Lawmakers from other parties have also been summoned before public prosecutors but only HDP deputies have refused to testify.

Among the charges HDP lawmakers face are alleged offenses of spreading terrorist propaganda in relation to comments made in October 2014, after Daesh militants entered the Syrian border town of Kobani, also known as Ayn Al-Arab.

Demirtas and other HDP figures urged residents to take to the streets. The ensuing week of violent demonstrations left dozens of people dead, including two police officers and saw hundreds of people injured.

The government has accused the HDP of having links to the PKK, which is listed as a terrorist organization by Turkey, the EU and U.S.