Nigeria, July 23 -- Nearly two weeks after the Nigerian military announced that its troops had killed a media operative of the Islamic State West Africa Province (ISWAP) during a night attack in Borno State, it released screenshots from a video it said showed the terrorist group acknowledging the man's death.

The military identified the slain operative as Abu Salim al-Barnawi, describing him as a former terror commander who later became one of ISWAP's chief photographers and propaganda operatives. It argued that the obituary released by the group demonstrated the growing pressure being mounted by troops under Operation Hadin Kai, a joint task force in the North-east.

The acting spokesperson for the task force, Mohammed Goni, said the ki...