The 17-storey Plasco Trade Center collapsed in Tehran on Thursday morning while the firefighters were trying to extinguish the fire in the building, IRNA reported.
The Iranian government announced a day of mourning on Saturday.
In his message, the Syrian ambassador sympathized with the Iranian nation, particularly Supreme Leader, Ayatollah Seyyed Ali Khamenei, and the bereaved families of the victims.
He extended condolences to the families of firefighters, who 'bravely sacrificed themselves for their country and their people.'
EghtesadOnline: Syrian ambassador to Iran, Adnan Mahmoud, on Saturday condoled with the Iranian nation and government on the tragic building collapse, which killed and injured dozens of firefighters and civilian people in the Iranian capital on Thursday.