A tunnel collapsed on five Palestinian Islamic Jihad (PIJ) tunnel operatives late Monday night in the south Gazan town of Khan Younis, leaving one dead, two wounded, and two additional missing, according to Saraya al-Quds, the military wing of the Palestinian Islamic Jihad.“One of our fighters in the Khan Younis Brigade rose to heaven as a martyr Monday night while carrying out preparatory work,” a statement published on its website said. The statement identified the deceased tunnel worker as 28-year-old Salah Mohammed al-Astal, who succumbed to his wounds in transport to the hospital.“We emphasize that the blood of the martyrs will remain an illuminating lamp for our fighters on the path of might and dignity,” the statement added. Palestinian Civil Defense units evacuated the two wounded tunnel operatives to a nearby hospital for treatment and are still searching for the two missing tunnel operatives.This tunnel collapse comes nine days after another tunnel collapsed on PIJ tunnel operatives in the north Gazan town of Beit Hanoun. The exact reason behind the recent tunnel collapses remains unclear. Prime Minister Benjamin Netanyahu revealed in April that Israel has developed a cutting-edge tunnel technology to locate tunnels.