Russia says its consulate general in Isfahan suffered damage after a nearby provincial government building was struck on Sunday.
Foreign ministry spokeswoman Maria Zakharova said the force of the explosion shattered windows at the consulate and in surrounding residential properties, while also throwing several staff members backwards.
She said no one was killed or seriously hurt in the incident.
Zakharova condemned any strike affecting diplomatic or consular sites, saying such actions breach international law.
She urged all sides to uphold the protection afforded to diplomatic premises and to avoid endangering the staff working inside them.