Gulten Kisanak and Firat Anli are being investigated for links to a terror organisation.
The co-mayors of Turkey's southern city of Diyarbakir, Gulten Kisanak and Firat Anli, have been arrested as part of an anti-terrorism probe. The officials will be investigated for assisting PKK, which is a designated terror organisation.
People's Democratic Party (HDP), which is popular in Diyarbakir, condemned the arrests on Twitter on late Tuesday night and called on its supporters to protest on Wednesday. Small groups of people were seen demonstrating in the city in pictures posted on social media.
In September, 24 municipality administrators, who were HDP members, were removed from office for suspected links to PKK. They were replaced with state-appointed officials.
"It has been understood that Gultan Kisanak [...] made remarks that were [in favour of] the terrorist organisation during Novruz activities organised by PKK terrorist group," said the chief prosecutor's office in Diyarbakir in a statement. Kisanak has been accused of sending official vehicles to PKK funerals and of participating in "unlawful meetings and demonstrations".
According to the statement, Firat Anli authorised the use of municipality vehicles to construct a cemetery for members of the outlawed group in 2014.
Turkey's President Tayyip Erdogan has said removing officials accused of having ties with the PKK is the main component of the fight against the group.