"Today, two of IRGC's Ansar forces were martyred in Syria. Reports of the martyrdom of 15 people are wrong," Iran's Tasnim news agency quoted Ramezan Sharif, a spokesman for the IRGC, as saying.
"Abdollah Bagheri Niaraki and Karimi were martyred in Syria while protecting a religious site near Aleppo."
The spokesman gave no first name for Karimi.
Niaraki, who for a while was the bodyguard of former hardline president Mahmoud Ahmadinejad, was killed on Thursday, the semi-official Fars news agency reported.
Iran is the main regional ally of Syrian President Bashar aAssad and has provided military and economic support during Syria's four-year-old civil war.
Tehran says it has been offering "military advice" to the Syrian army in its fight against Islamic State militants and other rebel groups, and that it has sent fighters only to defend Shiite shrines.
Sources told Reuters this month that hundreds of troops had arrived since late September to take part in a major ground offensive planned in west and northwest Syria, in the biggest deployment of Iranian forces yet.
Sharif said the presence of the IRGC "has increased since the recent field developments in Syria", but gave no further details.
Four Iranian commanders were killed this month fighting in Syria, and an IRGC commander was killed in June.
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