The Hamas-run health ministry in Gaza says at least 90 Palestinians have been killed in an Israeli air strike on a designated humanitarian area.
About 300 people have been injured, according to the health ministry's statement, in an attack which Israel says targeted senior Hamas leader Mohammed Deif and his deputy Rafa Salama.
In a news conference on Saturday evening, Israeli Prime Minister Benjamin Netanyahu said there was "no certainty" that either of them had been killed.
Comments