Israel has resumed its air strikes on Hamas-controlled Gaza, after Israel's brief truce was met with continuing rocket fire.
Israel had earlier accepted an Egyptian ceasefire proposal and halted operations on Tuesday morning.
But the armed wing of Hamas rejected the initiative as a "surrender".
Palestinian officials say at least 192 people have been killed by Israeli air strikes launched eight days ago to stop militants firing rockets into Israel.
At least four Israelis have been seriously injured since the violence flared, but none have been killed.
Kerry condemnation The Israel Defense Forces said about 50 rockets had been fired into Israel during the six hours it had halted air strikes on Tuesday.