Hamas's military wing, Izzadin Kassam, said Friday that the previous day's deadly blast in the northern Gaza town of Beit Lahiya was caused by an accident as operatives were "preparing for a special jihad operation." Eight people, including an infant girl, were killed in the powerful explosion, which flattened the home of a Hamas operative. Hamas initially blamed Israel for the blast, but the IDF immediately said that it was not involved, pointing to a possible "work accident," most likely caused by terrorists' faulty handling of explosives. Also killed in the explosion were the finance director in the Hamas Interior Ministry - who was also a member of Izzadin Kassam - a commander of the Hamas anti-aircraft unit and a commander of the group's rocket manufacturing unit, Israel Radio reported. Rockets began to fly shortly after the blast, with more than 50 mortar shells, Kassams and Katyusha rockets fired into Israel. An Israeli woman was moderately wounded by shrapnel in an attack on Kibbutz Yad Mordechai shortly after noon and evacuated to Barzilai Hospital in Ashkelon. A number of fires broke out following the attack. Meanwhile, several people were treated for shock after a Grad-type Katyusha rocket was fired at Ashkelon. A state of emergency was declared in the Hof Ashkelon Regional Council and residents were instructed to enter fortified rooms. The attacks continued Friday, with two Kassam rockets and a mortar shell landing close to three western Negev neighborhoods. No one was wounded and no damage was reported. Also Friday, a 10-year-old boy was seriously injured as a mortar shell dud exploded near the Negev town of Shivta. The boy was taken by his family to Shivta Junction and he was then evacuated by helicopter to Soroka Hospital in Beersheba. Overnight Thursday, three Hamas terrorists were killed in an IAF strike in the northern Gaza town of Jabalya, Palestinians reported. The IDF said it hit a terror cell about to fire rockets from a cemetery. The strike brought the number of Palestinians killed Thursday in various incidents across the Gaza Strip, including the Beit Layiha blast, to 14. Also Thursday, IDF troops killed two Palestinian gunmen in a clash in northern Gaza, and Dr. Moaiya Hassanain of the Gaza Health Ministry said another person was killed in an IAF strike in southern Gaza. The IDF said aircraft hit a rocket squad. In addition, three Palestinian gunmen were killed by IDF soldiers after they were spotted placing a bomb along the Gaza border. As mortar shells exploded near the border, IDF troops spotted a bulldozer approaching the security fence in northern Gaza near Kibbutz Netiv Ha'asara. Soldiers fired at the vehicle, whose occupants escaped. IDF sources said the bulldozer was part of an elaborate Hamas plan to infiltrate Israel.