The 72-hour humanitarian truce between Israel and Hamas was over within hours, with 25 Palestinians killed in southern Gaza.
Israel has been blamed for killing 15 Palestinian civilians sheltering in a UN school in a day which saw 120 Palestinians killed and no end for the conflict in sight.
More than 100 Palestinians have been killed as Israel intensified its bombardment of Gaza after a weekend of broken truces.
UN Secretary General Ban Ki-moon has called for an immediate end to the violence in Gaza that has left more than 1,000 people dead and the area in a “critical condition”.
The UN Security Council has called for an “immediate and unconditional humanitarian ceasefire” in Gaza, but both the Israeli and Palestinian envoys to the UN criticised the statement.