Five Iraqi Kurdish peshmerga troops were killed Saturday in a clash with fighters of Turkey's outlawed Kurdistan Workers Party (PKK), a senior Iraqi Kurdish official said.
The PKK maintains rear-bases in northern Iraq which have come under renewed assault by Turkish forces since April.
Two peshmerga troops were also wounded in Saturday's clash in the Mount Matin district of Dohuk province, said Serbast Lazkin, deputy minister for peshmerga affairs in Iraqi Kurdistan's autonomous regional government.
The People's Defence Forces (HPG), the armed wing of the PKK, accused the peshmerga of entering "a conflict zone in Matin" between it and Turkey "which wants to occupy Iraqi Kurdistan".
"These peshmerga movements are a stab in the back for the PKK and we refuse their entry into an area under our control," it said in a statement.
The PKK's pan-Kurdish agenda has often put it at odds with Iraq's autonomous Kurdish government, which has sought to maintain good relations with Ankara.
The peshmerga affairs ministry has called on "everyone to respect the borders of Kurdistan and to refrain from endangering its security and stability."
The federal government in Baghdad has taken a stronger line, condemning repeated air and ground incursions into Iraq by Turkish forces.
Turkey has carried out a string of air raids and the occasional ground incursion since it announced its latest offensive in April.
Most of them have targeted PKK rear-bases in the Mount Qandil area further east.
But President Recept Tayyip Erdogan has warned he may widen the offensive to include the Makhmur district further south, which is directly ruled by the federal government in Baghdad.
The district hosts a UN-supported camp housing thousands of Kurdish refugees from Turkey that Ankara sees as a recruiting ground for PKK fighters.
"If the United Nations does not clean up this district, we will take care of it in our capacity as a UN member state," Erdogan warned earlier this week.
Turkish troops have maintained a network of bases in northern Iraq since the mid-1990s on the basis of security agreements struck with Saddam Hussein's regime.
The PKK has waged a rebellion in the mainly Kurdish southeast of Turkey since 1984 that has claimed more than 40,000 lives.