The PKK which has been waging an insurgency against the Turkish state since 1984, a conflict that has killed 40,000 people, many of them civilians, denied responsibility.

It has training camps and bases in autonomous Iraqi Kurdistan.

"Artillery fire targeted Bamarni sector, killing two civilians -- minors -- and injuring two other civilians," Warchine Suleimane, head of a local district, told AFP.

Relatives said that two children aged between 10 and 13 were killed by the fire.

They spoke to AFP at a mosque in the town of Dohuk, where the bodies were taken for funeral preparations.

In a statement, Kurdish counter-terror forces accused the PKK of "firing two rockets on the village of Ardana in Bamarni sector", and they put the toll at two dead and two injured.

The PKK said in response that "we categorically deny" the allegation that its forces were responsible for firing the projectiles.

It accused Iraqi Kurdish authorities of attempting "to whitewash Turkey's war crimes" in northern Iraq.

Ankara has launched a series of operations against PKK fighters in Iraq and Syria, the latest one in northern Iraq beginning in April.

The orchards hit by the projectiles are located close to a Turkish military base.

Ankara and its Western allies brand the PKK a terrorist organisation.

Iraqi Kurdistan has complicated relations with the PKK because its presence in the region hampers vital trade relations with neighbouring Turkey.

Ankara's defence ministry said Thursday that a Turkish soldier was killed in an operation against the PKK, taking Turkish military fatalities in northern Iraq since Tuesday to six.

Last week, at least six people, including three civilians, were killed in northern Iraq by drone strikes that local officials said were carried out by Turkey.