The daytime assault was followed by a machine-gun attack on a police bus in Diyarbakir, the main city of Turkey's Kurdish-majority southeast, which claimed five lives.
The bus came under fire just as parliament in Ankara extended by one year the government's mandate to order cross-border military operations in northern Iraq against the PKK.
Ankara has accused the autonomous Kurdish administration of northern Iraq of tolerating the PKK on its territory and even aiding the fighters, who, it says, obtain weapons and explosives in the region for attacks against Turkish targets across the border.
Recep Tayyip Erdogan, the prime minister, is under pressure to step up action against the PKK and toughen its stance towards the Iraqi Kurds.
The country's civilian and military leadership is scheduled to convene on Tuesday to outline fresh measures to combat the PKK, after an intitial meeting on Thursday.