An Iranian pilot was killed defending Shi'ite Muslim holy sites in neighboring Iraq, Iran's state news agency said, in the first official report of an Iranian death related to an upsurge in violence there since June.
Shoja'at Alamdari Mourjani, who was buried in the Iranian city of Shiraz on Friday, was killed while fighting Sunni jihadists in Samarra, north of Baghdad, it said.
Iran's official IRNA news agency did not say whether the pilot died while flying sorties or fighting on the ground, or whether he was in Samarra of his own initiative or on behalf of the Iranian state.
Iraq's Shi'ite-led government is fighting an insurgency by Sunni rebels led by an al-Qaida splinter group, the Islamic State of Iraq and the Levant (ISIL), who consider Shi'ites heretics.
Shi'ite power Iran has said it will not hesitate to defend Shi'ite holy sites in Iraq if necessary, but it has also said Iraq itself is capable of putting down the rebellion.
ISIL has seized territory across the north and west of Iraq, as well as border posts, oil fields, and the north's largest city, Mosul, since June 10.
Shi'ite militias have also joined the fray on the Baghdad government's side against the militants.
Followers of the Shi'ite cleric Muqtada al-Sadr have formed an army under the name of the al-Salam (Peace) brigades to defend Shi'ite holy shrines.
The Shi'ite al-Salam brigades have been stationed in Samarra since ISIL captured large swathes of territory in the north of country.
Kadhim al-Isawi, commander of the al-Salam brigades, said that his militia were deployed along with other government troops to defend the holy shrine of al-Askari.
The golden-domed al-Askari mosque in Samarra is one of the holiest shrines in Shiite Islam.
A 2006 bombing at the same site exacerbated already severe sectarian tensions between Sunnis and Shi'ites, fueling a war that killed tens of thousands of people over the next two years.
More than 6,000 people have been killed in violence across Iraq this year, as its sectarian balance comes under acute strain from the civil war in neighboring Syria.
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 toward Shi'ism - a branch of Islam overwhelmingly practiced in Iran - have raised alarm in Tehran.
Some information for this report provided by Reuters, AFP and AP.