The Islamic State jihadist group said Wednesday that its leader Abu Hasan al-Hashimi al-Qurashi has been killed in battle and announced a replacement to head up its remaining sleeper cells.A spokesman for IS said Hashimi, an Iraqi, was killed "in combat with enemies of God", without elaborating on the date or circumstances of his death.The US military's Central Command (CENTCOM) said Hashimi had been killed in an operation carried out by rebels of the Free Syrian Army in Daraa province in southern Syria in mid-October.