"Heroic commandos of the heroic Turkish Armed Forces are in northern Iraq," the defence ministry said in a tweet without specifying how many soldiers were involved.

Turkish media said commando forces landed in the Metina region from helicopters while warplanes dropped bombs on Kurdistan Workers' Party (PKK) targets.

Turkish television showed images of paratroopers jumping from helicopters and camouflaged soldiers firing guns.

The PKK, listed as a terror group by Turkey and much of the international community, has for decades used Iraq's northern mountains as a springboard for its insurgency against the Turkish state.

The Turkish army regularly conducts cross-border operations and air raids on PKK bases in northern Iraq.

In February, Turkey launched an operation dubbed "Claw-Eagle 2" against PKK rebels holed up in the northern Iraqi region of Dohuk.

That operation created controversy because it was designed in part to rescue 12 Turkish soldiers and an Iraqi held captive by the PKK in a cave.

Turkey accused the PKK of executing the 13 men before they could be freed.

The Kurdish insurgency against the Turkish state is believed to have killed tens of thousands of people since being launched in 1984.