Foreign ministry spokesman Abbas Araqchi was quoted as saying he "strongly condemned the terrorist attacks" which occurred outside two mosques during weekly Muslim prayers yesterday.
He denounced "takfiri (Sunni Muslim extremist) groups who seek to sow division to undermine Lebanese national unity and the peaceful coexistence of different communities" in the country.
The spokesman said such people were playing into the hands of "the Zionists," in reference to Israel.
Iran is the main regional backer of the powerful Lebanese Shiite movement Hezbollah and President Bashar al-Assad's regime in war-torn Syria.