Forty-eight people were wounded Monday after an explosive-laden vehicle was detonated in the eastern province of Van, local authorities said.
The blast hit a government checkpoint at the provincial offices of Turkey's ruling Justice and Development Party (AKP).
Images broadcast by CNN Turk showed the badly damaged AKP building. Two of the injured were identified as police officers.
Nobody claimed immediate responsibility for the attack, but the outlawed Kurdistan Workers' Party (PKK) - which targets primarily Turkish security forces - is active in the region.
The Turkish Army launched an offensive against the PKK in the summer after a two-year truce broke down.
The imprisoned head of the PKK made his first public comments Monday after a period in isolation, calling for peace.
"The blood, the tears have to stop," he said in a message read out by his brother, according to the broadcaster IMC TV.
Ocalan, who was incarcerated on Imrali Prison Island in 1999 and was last allowed visitors in 2015, also called for new talks with the government.
"If the state is ready [for talks], let it send two people here. Yes, it is a difficult problem, but our plan stands and we will solve this problem in six months," his statement read.
On Sunday, the Turkish government sacked dozens of pro-Kurdish mayors and councillors in the south-east of the country and replaced them with pro-government administrators.
President Recep Tayyip Erdogan described the move as long overdue on Monday.
"In my opinion, this move has come late. We should have made this move earlier," he told state-run news agency Anadolu in Istanbul. "That was my wish earlier," he said.
Four districts in Van were hit by the purge.
It was unclear if Monday's attack had anything to do with the dismissal of the pro-Kurdish mayors and councillors.