The Iraqi defence ministry (MoD) has announced the death of Islamic State (Isis) second-in-command Abu Alaa al-Afri, a former Iraqi physics teacher who was reportedly in charge of the jihadist group after the wounding of caliph Abu Bakr al-Baghdadi.

A video posted on the MoD YouTube page showed an air strike of the US-led coalition targeting a mosque where al-Afri was allegedly meeting other IS leaders, including the group's supreme judge.

The Guardian reported on 1 May that Baghdadi had a serious spinal injury meaning he would never again be able to lead the terrorist group. Two doctors from Mosul travelled to his northern Iraqi hideout to treat the caliph after a US raid over two months ago.

Baghdadi has been an elusive figure since a video emerged of him giving a sermon in a Mosul mosque in which he anointed himself caliph – or leader – of IS. The only other image available of him is from 2010, when he was arrested but later released by the US in 2004.

It was reported in April that he had been killed in a US air strike somewhere in northern Iraq, but it later emerged he had only been injured in the attack. The Pentagon admitted it carried out the strike but had been unaware Baghdadi was there.

Al-Afri, who is based in the country's second-biggest city, Mosul, has allegedly become more charismatic among the group's leadership. Newsweek quoted Iraqi government adviser Dr Hisham al Hashimi as saying al-Afri "had begun to head up Daesh [Arabic term for Isis] with the help of officials responsible for other portfolios".

The IS leader was a physics teacher in Tal Afar, an Iraqi city in the north-western Nineveh province and has published several articles and religious studies of his own. Hashimi said: "He is a follower of Abu Musaab al-Suri."