More than 220 Iranian soldier have been killed in Syria in the last six months alone, according to Iranian media reports cited by Israel Radio.
Three of the soldiers were killed over the past day, the reports added, among them two Revolutionary Guard soldiers and a militiaman from the loyalist Basij paramilitary force.
As noted, the figures only count Iranian combat deaths since last October, underscoring the mounting death-toll for Tehran as it continues its direct and indirect military support for the Assad regime in Syria's five-year civil war.
Iranian and Hezbollah fighters have been involved in several fierce battles against rebels and ISIS forces in northern and western Syria in particular over the past several weeks. On Tuesday, Hezbollah confirmed that two of its most senior commanders in Syria were killed battling ISIS in Homs.
The latest figures come as Iran says it deployed a contingent of elite army "commandos" to bolster pro-regime forces.