The fragile ceasefire in Gaza faced its first major test Sunday as an Israeli security official said the transfer of aid into the territory was halted after Hamas militants killed two sold

Aid trucks have been entering Gaza and Israel resumed preparations to open the main Rafah crossing as Hamas handed over more bodies of dead hostages, following a dispute over the implementation of the ceasefire.

An Israeli security official said the transfer of aid into the territory is halted "until further notice," the first major test of the ceasefire.

Israel allows aid to resume through Rafah after recovering bodies of four captives, as agencies warn Gaza's displaced face worsening hunger and delayed relief.

Israel was expected to allow Gaza's sole border crossing to the outside world to reopen Wednesday to allow humanitarian aid into the devastated territory as part of a US-backed ceasefire deal.