Even as world leaders welcomed it, the four-day ceasefire between Hamas and Israel is an unlikely harbinger of a longer truce to the conflict. Almost before the ink was dry on the agreement to allow the exchange of hostages and the flow of humanitarian aid into the embattled Gaza strip, fierce fighting resumed in northern Gaza. Israel signalled that the hostage exchange would be delayed until Friday — it was due to come into force on Thursday at 10 am local time. Under the pact, Hamas agreed to release 50 women and children under the age of 19 in return