Falling debris damaged a house in the city centre, police and army officials told AFP, speaking on condition of anonymity.

There were no reports of any direct casualties but the police official said a carpenter working on a nearby building site had been admitted to hospital after a fall.

"A Turkish drone which penetrated Iraqi airspace has been shot down," the deputy air defence commander for Kirkuk, General Abdel Salam Ramadan, told a press conference at the site of the downing.

The aircraft had come "from the direction of Sulaimaniyah", second city of the Kurdish autonomous region to the north, Ramadan said.

Ethnically mixed Kirkuk and its surrounding oil fields do not form part of the autonomous region but are directly administered by the federal government in Baghdad.

Turkey has maintained dozens of military bases in northern Iraq for the past quarter of a century as part of its campaign against militants of the Kurdistan Workers' Party (PKK).

Its troops routinely carry out operations against PKK targets but it comments on them only sporadically.

The Iraqi federal government discreetly outlawed the PKK as a "banned organisation" in March and earlier this month agreed a military cooperation deal with Ankara that will see joint training and command centres set up in the fight against the militants.

The leftist group, which has waged a deadly on-off insurgency against the Turkish state since 1984, is blacklisted as a "terrorist organisation" by Ankara and its Western allies.