"The Turkish ambassador will be called in to receive a letter of protest addressed to the Turkish president", Recep Tayyip Erdogan, Rashid's office said in a statement.

"Mercy be on the martyrs of Iraq, the civilian and military heroes killed by repeated Turkish attacks."

Turkish authorities have not commented on Monday's strike which killed three members of the counterterrorism forces of Iraq's autonomous Kurdish region and wounded three others at Arbat airfield, southeast of the city of Sulaimaniyah.

While such attacks against the Iraqi Kurdish security services are extremely rare, Ankara is leading a quickening campaign in northern Iraq and neighbouring Syria, targeting Kurdish fighters.

A senior military official in Baghdad said that the drone which killed the counterterrorism officers had originated in Turkey.

Around 5:00 pm (1400 GMT) on Monday, "the drone entered Iraqi airspace, crossing the border from Turkey, and bombarded the Arbat airfield," which is mainly used by crop-spraying aircraft, said General Yehya Rassoul, spokesman of the federal armed forces commander in chief.

"This attack constitutes a violation of Iraq's sovereignty", he said, adding: "Iraq reserves the right to put a stop to these violations."

"These repeated attacks are incompatible with the principle of good neighbourliness between states. They threaten to undermine Iraq's efforts to build positive and balanced political, economic and security relations with its neighbours," Rassoul said.

- UN condemns attack -

On Sunday, a Turkish drone strike killed a senior official and three fighters of the Kurdistan Workers' Party (PKK) in the Sinjar Mountains of northwestern Iraq, Iraqi Kurdish authorities said.

Ankara and its Western allies classify the PKK as a "terrorist" organisation.

The UN mission in Iraq condemned the attack on Arbat airfield.

"Attacks repeatedly violating Iraqi sovereignty must stop," it said. "Security concerns must be addressed through dialogue and diplomacy -- not strikes."

The Turkish army rarely comments on its strikes in Iraq but routinely conducts military operations against PKK rear-bases in Kurdistan as well as in Sinjar district.

The PKK has been waging a deadly insurgency against the Turkish state for four decades and the conflict has repeatedly spilt across the border into northern Iraq.

Turkey operates dozens of military posts in northern Iraq initially established under an agreement struck in the eighties with the government of executed dictator Saddam Hussein.

In April, Baghdad accused Ankara of carrying out a "bombardment" near Sulaimaniyah airport while US soldiers and the commander of the Syrian Democratic Forces -- a US-backed alliance dominated by the PKK's Syrian Kurdish ally, the People's Defence Units (YPG) -- were present.

That strike too drew condemnation from the office of president Rashid, who is himself a Kurd.

- 'Significant progress' -

But Iraqi Kurdistan has for decades hosted several Iranian Kurdish opposition groups hostile to the Islamic republic.

A year ago, Iran repeatedly bombed the groups' positions, accusing them of infiltrating its territory in order to lead attacks against its forces.

Iran also accused them of involvement in protests that exploded after the death in custody of young Iranian Kurdish woman Mahsa Amini.

Tehran set September 19 as a deadline and threatened retaliation if Baghdad failed to implement a "security agreement" which stipulated the disarming of these groups and their settlement in camps far from the Iranian border.

Baghdad said Tuesday it had "respected its commitment" and had transferred these groups "to an area away from the border".

"These groups were disarmed ahead of giving them refugee status," added the statement published by a committee responsible for implementing the agreement, specifying Iraqi federal army border guards were deployed in the recently evacuated border areas.

Asked about the agreement, the UN's Iraq envoy Jeanine Hennis-Plasschaert said "significant progress has been made".

"All sides are genuinely committed to the agreement. Long term security is essential for all," she told AFP.