The Nabi Yunus shrine was built on the reputed burial site of a prophet known in the Quran as Yunus and in the Bible as Jonah.
"Islamic State (ISIL) completely destroyed the shrine of Nabi Yunus after telling local families to stay away and closing the roads to a distance of 500 meters from the shrine," said an official at the Sunni endowment.
The endowment official, who spoke on condition of anonymity, and Mosul residents said that it took the extremists an hour to rig the shrine with explosives.
"They first stopped people from praying in it, they fixed explosive charges around and inside it and then blew it up in front of a large gathering of people," AFP quoted a witness as saying.