Turkish warplanes have bombed 21 bases belonging to the Kurdistan Workers' Party (PKK) both inside the country and over the border in northern Iraq, the military has said.

The raids on Tuesday came after PKK fighters killed 15 Turkish soldiers near Semdinli in the country's southeast.

According to a military statement released on Tuesday, the planes bombed PKK bases in the Avasin Basyan region in Iraq as well as the Buzul and Iki Yaka mountains in Turkey's southeast.

"The planes returned safely to base after successfully completing their mission," the statement said, without disclosing any further details.

Fierce clashes

The raid was the fourth strike against PKK bases inside Iraq since Friday's ambush which killed 15 soldiers, prompting the most intense fighting between Turkish troops and Kurdish fighters in eight months.

The military said troops fought back, killing at least 23 rebels, but that two soldiers were still missing after the attack.

Turkey accuses the PKK of using the region as a sanctuary from where to plan and carry out deadly attacks against Turkish troops in the south and eastern regions of Turkey. 

Troops and rebels have regularly exchanged fire in the border regions in recent months.

Ankara blames the PKK for a series of attacks on Turkish targets, notably a series of blasts in Istanbul in July.

More than 40,000 people are thought to have been killed since 1984, when the PKK launched its campaign for a Kurdish homeland in southeastern Turkey.