A car bomb blast outside a police building in south-eastern Turkey killed a police officer and five civilians, including a 5-month-old baby, Prime Minister Ahmet Davutoglu said Thursday.
The governor's office in Diyarbakir province also reported 39 people were injured in the attack, which authorities were blaming on the Kurdistan Workers' Party (PKK).
The police headquarters and surrounding buildings were heavily damaged in the blast, which took place in middle of the night.
The assault on the police station in Cinar district lasted 40 minutes and also involved attacks with firearms and rockets. Members of security forces and civilians were among the injured.
Deputy Prime Minister Numan Kurtulmus on Twitter condemned the "treacherous" attack.
Heavy clashes have been going on for six months in the mostly Kurdish south-eastern Turkey, after a two-year ceasefire between the state and the PKK broke down.
Hundreds have died in clashes since July while thousands have been forced to flee their homes. Turkey, a NATO member, is also launching airstrikes against PKK bases in northern Iraq.
The Kurdish militants, listed by the United States and the European Union as a terrorist organization, are fighting for greater autonomy for the minority group, which complains of systemic discrimination.
Human rights groups have condemned the fighting, criticizing the strict round-the-clock curfews the military and police are imposing on neighbourhoods in several provinces, including Diyarbakir.
The fighting with the Kurdish militants in the south-east comes on top of Turkey's efforts to get a grip on attacks by the Islamic State extremist group.
This week, a suicide bomber killed 10 German tourists in Istanbul, with officials pointing the finger at Islamic State.