Prime Minister Benjamin Netanyahu said Tuesday that Israel would push on with fighting in Gaza until "absolute victory" despite suffering one of its toughest days of the military offensive.

"Yesterday we experienced one of the most difficult days since the war erupted," said Netanyahu. "In the name of our heroes, for the sake of our lives, we will not stop fighting until absolute victory."

He said the military was "investigating the tragedy" in which 21 soldiers were killed when buildings exploded in central Gaza, bringing the single-day Israeli death toll to 24.