Turkey said on Saturday that its fighter jets hit militant camps of the Kurdistan Workers Party (PKK) in northern Iraq overnight, and Turkish ground forces struck the PKK and Islamic State fighters in northern Syria.
The strikes against PKK targets are likely to be a major blow to the stalled Kurdish peace process.
Turkey launched its first-ever air attack against Islamic State targets in Syria early on Friday, promising more decisive action against both the jihadists and Kurdish militants.
Fighter jets hit PKK targets in several locations in northern Iraq, including warehouses, "logistic points", living quarters and storage buildings, Prime Minister Ahmet Davutoglu's office said.
The outlawed PKK, deemed a terrorist organization by Ankara and Washington, has waged a three-decade insurgency against Turkey for greater Kurdish autonomy.
Turkey stepped up its role in the US-led coalition against the militant group Islamic State on Friday. As well as launching its first air strikes against the hardliners in Syria, it promised to open up its air bases to the United States.
Police also detained more than 300 suspected Islamic State and PKK members in a police crack down on Friday, Prime Minister Davutoglu said after vowing to fight all "terrorist groups" equally.
Turkey's more active role comes after a suspected Islamic State suicide bomber killed 32 people, some of them Kurds, this week in the border town of Suruc. That touched off a wave of violence in the mainly Kurdish southeast, with the PKK killing at least two police officers, calling it retaliation for the suicide bombing.
Many Kurds and opposition supporters have suspected Turkish President Tayyip Erdogan and the ruling AK Party of covertly backing Islamic State against Kurdish fighters in Syria, something the government has repeatedly denied.
Erdogan took a big political risk in starting peace talks in 2012 with the Kurds, who represent nearly 20 percent of Turkey's population, but they now blame him for backtracking on promises.
On Friday, Erdogan said he had told US President Barack Obama that the PKK, which he calls a separatist organization, would be a focus for attacks.
