An Iranian pilot has been killed while fighting against Sunni jihadists in Iraq, state media reported, in what is thought to be Tehran's first such military casualty.
Iran's official Islamic Republic News Agency (IRNA) did not say whether the pilot died while flying sorties or fighting on the ground.
Colonel Shoja'at Alamdari Mourjani was killed "defending" Shiite Muslim holy sites in the city of Samarra, north of Baghdad, it said on Saturday.
His death comes after Iranian declarations that it will provide its neighbour with whatever is needed to counter the Sunni militants who are laying siege to the Shiite-led government of Prime Minister Nouri al-Maliki.
Samarra is a major flashpoint in the fighting and is home to the Shiite Al-Askari shrine, which was bombed by Islamist extremists in February 2006, sparking a bloody Sunni-Shiite sectarian war that killed tens of thousands of people.
The reports of the pilot's death came as Iranian officials insist their assistance is not in the form of troops, but rather of weapons and equipment if Iraq asks for them.
The militants' advances and their boasts of animosity towards Shiism - a branch of Islam overwhelmingly practised in Iran - have raised alarm in Tehran.
President Hassan Rowhani vowed last month that Iran would protect Shiite holy sites in Iraq, including in Samarra.
Iranian officials have not yet commented on the report of the pilot killed in Iraq. But the Fars news agency appeared to confirm the IRNA report.