In an unusually strong rebuke, Prime Minister Mustafa al-Kadhemi warned Turkey that Iraq reserves the "right to retaliate," calling the artillery fire a "flagrant violation" of sovereignty.

Turkey launched an offensive in northern Iraq in April dubbed "Operation Claw-Lock", which it said targets fighters from the Kurdistan Workers Party (PKK).

The victims included Iraqi tourists who had come to the hill village of Parakh in Zakho district to escape sweltering temperatures further south in the country, according to Mushir Bashir, the head of Zakho region.

"Turkey hit the village twice today," Bashir told AFP.

A source in Turkey's defence ministry said that he had "no information reporting or confirming artillery fire in this area".

The artillery strikes killed nine and wounded 23, Zakho health official Amir Ali told reporters. He had earlier put the toll at eight dead, including two children.

- 'Bodies in the water' -

In front of a hospital in Zakho, Hassan Tahsin Ali spoke to AFP wearing a bandage around his head.

He said he was lucky to survive the deluge of fire that fell on the park and its water features, where visitors had been relaxing.

"We come from the province of Babylon," the young man said in a slow voice.

"There were indiscriminate strikes on us, there were bodies in the water," he added. "Our young people are dead, our children are dead, who should we turn to? We have only God."

Iraq's prime minister dispatched the country's foreign minister and top security officials to the site.

"Turkish forces have perpetrated once more a flagrant violation of Iraqi sovereignty," Kadhemi said on Twitter, condemning the harm caused to "the life and security of Iraqi citizens."

"Iraq reserves the right to retaliate against these aggressions and take all necessary measures to protect our people," Kadhemi added.

Designated as a terrorist group by Ankara and its Western allies, the PKK has been waging an insurgency against the Turkish state since 1984 that has claimed tens of thousands of lives.

Arbil, the capital of Iraqi Kurdistan, has complicated relations with the PKK as its presence in the region hampers vital trade relations with neighbouring Turkey.

The military operations have seen Turkey's ambassador in Baghdad regularly summoned to the Iraqi Ministry of Foreign Affairs.