The source said the pre-dawn assault targeted the desert post near Kirkuk, where remnants of the Islamic State group are active, as well as Kurdistan Workers' Party (PKK) rebels waging an insurgency against Turkey.

Both Baghdad's forces and those of Iraq's autonomous Kurdistan region claim the area where the assault occurred.

Iraqi Kurdish fighters are deployed about one kilometre (less than a mile) from the post that was attacked, said the source, who asked not to be identified.

No one has claimed responsibility for the attack.

Turkish forces regularly carry out military operations against Kurdish PKK forces, designated a terrorist group by Ankara and its Western allies.

The PKK has kept up a deadly insurgency for Kurdish self-rule in southeastern Turkey since the 1980s, and maintains rear bases in Iraq.

In early November, a Turkish drone strike in northern Iraq killed at least one PKK member, officials from Iraqi Kurdistan announced at the time.

In addition, neighbouring Iran, shaken by two months of anti-regime demonstrations, accuses Kurdish-Iranian opposition groups based in northern Iraq of stoking the "riots".

Iraqi Kurdistan hosts several Iranian Kurdish opposition groups, which have in the past waged an armed insurrection against Tehran.

In recent years their activities declined, but the wave of protests in Iran has fuelled tensions.

On Monday, Iran launched cross-border missile and drone strikes, killing at least one person according to local authorities.

Iran also carried out strikes in late September that killed more than a dozen people.

In the same region of Iraq, cells of the jihadist Islamic State group continue sporadic attacks against Iraqi soldiers and police, particularly in desert and mountain zones.

IS seized large swathes of Iraqi territory before the jihadists' defeat in late 2017 by Iraqi forces backed by a US-led military coalition.

That anti-IS coalition continued a combat role in Iraq until last December, but roughly 2,500 American soldiers remain.