"Based on accurate intelligence, an air strike by the coalition forces targeted the second in command of IS, Abu Alaa al-Afari," the ministry said in a statement on its website.
Abu Alaa al-Afari, whose real name is Abdul Rahman Mustafa Mohammed, is an ethnic Turkmen from the town of Tel Afar in northwestern Iraq, and is thought to be second in command of Islamic State after self-proclaimed caliph Abu Bakr al-Baghdadi.
On its website, the Iraqi defense ministry posted footage of the air strike on the "Martrys Mosque" in the village of al-Iyadhiya near Tel Afar, where Afari was a teacher and well-known preacher, according to a local official who asked to remain anonymous.
There was no way to independently confirm the defense ministry statement, and the Iraqi government has previously announced the death of Islamic State militants only for them to resurface alive.