Turkish artillery has shelled targets in Kurdish-controlled northern Iraq, according to Iraqi-Kurdish officials, though there were no immediate reports of casualties.
Jabbar Yawar, a spokesman for the Peshmerga security forces of northern Iraq, said on Friday that Turkish forces had shelled two areas in Dahuk province for two hours.
Earlier, Iraqi Kurdish television said Turkish military had bombed northern Iraq, but gave no details of any injuries or damage to property.
Turkey has targeted northern Iraq even the past, saying separatist Kurdish fighters are sheltered there.
The Reuters news-agency reported an unnamed Iraqi border guard official as saying there were no casualties in the shelling, which took place between 7am (04:00 GMT) and 9am (06:00 GMT).
The latest offensive came after Ankara vowed to pursue fighters of the Kurdistan Workers Party (PKK) inside northern Iraq.
Turkish warplanes repeatedly struck PKK targets in the mountainous north of Iraq in December and troops also made small-scale cross-border raids.
Turkey has also massed up to 100,000 troops on the border with Iraq.