The vast labyrinth used for smuggling and Hamas operations has long been a barrier to large-scale invasion
• Israel and Hamas at war – live updates
Israel’s heaviest aerial bombardment of Gaza of the war so far was aimed at Hamas’s extensive network of underground tunnels and bunkers, known to Israeli military planners as the “metro”.
A spokesperson for the Israel Defence Forces (IDF) said the strikes involving about 100 planes began after dusk and hit 150 underground targets associated with Hamas’s tunnel network, a system which has been years in the making.
