The rise of Izz al-Din al-Haddad in the chain of command suggests the group will hold firm to its position demanding a total end to the war before releasing all remaining hostages.

Hamas is seeking guarantees that a new U.S.-backed ceasefire proposal for Gaza would lead to the war's end, a source close to the militant group said on Thursday, as medics said Israeli strikes across the territory had killed scores more people.

More than 80 Palestinians were killed across Gaza on Thursday, according to health officials, as Israel intensified its strikes across the strip.