Iran's foreign ministry condemned this week's killing of a French priest, drawing a parallel with the recent decapitation of a young boy by jihadists in Syria, state media said Thursday.

"Such savage and abominable actions must be condemned regardless of the location," said ministry spokesman Bahram Ghassemi.

"We share the sadness of all... in the face of these inhuman, brutal and detestable actions."

Two jihadists, who had pledged allegiance to the Islamic State group, attacked a French church on Tuesday and murdered a priest by cutting his throat.

That came a week after a video emerged showing rebel fighters beheading a boy, said to be around 13, after capturing him north of Syria's second city Aleppo.

Iran gives political and military backing to the Syrian government of President Bashar al-Assad, and labels all rebel groups in Syria as "terrorists".