Six members of Iran's Revolutionary Guard Corps (RGC) have reportedly been killed in clashes in northern Syria. According to Iran's semi-official Fars News Agency, the six were killed in fighting that occurred in Syria's northern city of Aleppo. The slain soldiers will be buried on Thursday, the news agency said without providing further details. Syria has been racked by conflict since early 2011, when the regime of Bashar al-Assad cracked down on pro-democracy protests with unexpected ferocity. Shia Iran, for its part, is a staunch supporter of the Assad regime. Since late 2011, Iranian soldiers -- along with members of Lebanon's Shia Hezbollah group -- have been fighting alongside pro-Assad forces in Syria. According to Iranian media reports, more than 400 Iranian soldiers have been killed in the fighting in Syria since 2011.