A senior official from the elite Iranian Revolutionary Guard was killed along with 12 other fighters in the pro-government offensive in the strategic Syrian city of Aleppo, a security source told The Daily Star Thursday.
Colonel Mohsen Qajaryan was killed during battles against rebel forces in northern Aleppo as Syria's army and its allied forces, backed by Russian airstrikes, managed to regain control Wednesday over two Shiite villages in Aleppo, which had been beseiged by rebels for three years.
The source added that 23 other pro-government fighters were killed in the advance, which began Monday.
However, it is not clear if any Hezbollah fighters were among them.
At least 98 rebel fighters were also killed in the battles, as Russian warplanes backed the ground offensive.
The Russian fleet allegedly conducted 206 air raids on areas in northern Aleppo.
Turkey said on Thursday that tens of thousands of refugees from Aleppo, 50 km (30 miles) south of the Turkish border, were moving towards the border due to air strikes.
On Thursday, Hezbollah's Al-Manar television broadcast what it said was exclusive footage of Syrian government and allied fighters entering the villages of Nubol and Zahraa, which have been under siege by rebels for the past three years.
The Syrian army Wednesday also took control of part of the rebel supply route from opposition-held Aleppo to the Turkish border.
Rebels in the city are now surrounded from the south, east, and north, with only a single opening in the northwest leading into the neighboring opposition-held province of Idlib.
"Mass celebrations are being held in the streets of Nubol and Zahraa to welcome the troops and the breaking of the siege," Syria's state-run news agency SANA reported.
Fighters and residents waved the Syrian flag and the yellow Hezbollah flag, while some chanted pro-government slogans, including "God, Syria, Bashar and nothing else," in reference to Syrian President Bashar Assad.
Aleppo, Syria's pre-war commercial capital has been divided between loyalists in the west and rebels in the east since fighting erupted in the northern city in mid-2012.
Assad's forces backed by Hezbollah and other groups have encircled Aleppo from the west, south and east, and advanced from the north last week.
Additional reporting from AFP, Reuters