Two senior commanders of the Iranian Revolutionary Guard Corps (IRGC) have been killed in Syria, according to Iranian media.
Hamid Mokhtarband and Brigadier General Farshad Hassounizadeh died while assisting the Syrian government's battle against ISIL on Monday, reported the Tasnim and Fars news agencies and Press TV.
Their deaths come after another top commander, General Hossein Hamadani, was killed on Thursday night on the outskirts of Aleppo.
Press TV reported that Hassounizadeh was in Syria to "defend the holy shrine of Hazrat Zeinab, the granddaughter of Prophet Muhammad (Peace Be Upon Him), in the country’s capital of Damascus."
The Islamic Republic denies having any military forces in Syria, but says it offers "military advice" to Assad's forces in their fight against "terrorist groups".
An IRGC statement on Friday said that Hamadani had been advising the Syrian military and defend Shia shrines in the country.
Iran is the main regional ally of Syrian President Bashar al-Assad, and has provided military and economic support during Syria's four-year-old civil war.
Assad's other longtime ally, Russia, launched its air campaign in September, saying it would target ISIL. Its planes, however, have also hit other rebel groups opposed to Assad, including groups backed by Washington.
More than 250,000 people have been killed in Syria's civil war, which began in 2011.