Clearing the surface of Gaza of unexploded ordnance will likely take between 20 to 30 years, according to an official with aid group Humanity & Inclusion, describing the enclave as a "horrific, unmapped minefield."

More than 53 people have been killed and hundreds injured by lethal remnants from the two-year Israel-Hamas war, according to a U.N.-led database, which is thought by aid groups to be a huge underestimate.

A U.S.-brokered ceasefire this month has raised hopes that the huge task of removing them from among millions of tons of rubble can begin.