For a quarter of a century, Ankara has maintained dozens of military bases in northern Iraq where it regularly conducts operations against PKK commanders and rear bases.

In Friday's strike, "a drone of the Turkish army targeted a PKK vehicle near Nalparez", a village in Sulaimaniyah province on the road to the Iranian border, the autonomous Kurdish region's counter-terrorism department said in a statement.

"A senior PKK official, a fighter and a driver were killed."

The head of Nalparez subdistrict, Himen Ibrahim, gave the same toll.

It was the fourth strike this week on the PKK that the authorities in Iraqi Kurdistan have attributed to Ankara. Six rebels have been killed.

The Turkish military rarely comments on individual strikes in northern Iraq, although it routinely carries out both air and ground operations against the group, which it blacklists as a terrorist organisation.

On Thursday, the Turkish defence ministry announced that at least six soldiers had been killed in clashes with the PKK in northern Iraq.

Both the Kurdish authorities in regional capital Arbil and the federal government in Baghdad have long been accused of not doing enough to stop Turkey's frequent resort to military action on Iraqi soil in its nearly four-decade struggle against the PKK.

Statements condemning the violation of Iraqi sovereignty are periodically issued, particularly when there are civilian casualties.

But critics say both Arbil and Baghdad are more concerned with protecting trade and investment ties with Ankara.

On July 25, the office of Prime Minister Mohamed Shia al-Sudani announced a forthcoming visit to Iraq by Turkish President Recep Tayyip Erdogan, but no date has yet been set.

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