The Israeli military has started pumping seawater into Hamas’s vast complex of tunnels in Gaza, The Wall Street Journal reported, citing US officials. The flooding of Hamas’s tunnels is part of an intensive effort to destroy the underground infrastructure that has underpinned the group’s operations. Israel is employing various techniques, including flooding tunnels with Mediterranean water, in an early effort to clear and destroy the tunnels. Israeli officials say Hamas’s underground system has been crucial to its operations on the battlefield.