A large explosion in the northern Gaza town of Beit Lahiya on Tuesday killed an eight-year-old boy and his six-year-old sister and injured five other children, Palestinian health officials said. Witnesses said a group of children stumbled upon a homemade rocket or a mortar shell and began playing with it. The device exploded, injuring all seven children, one of whom died later of her wounds. Another boy was in critical condition. Moaiya Hassanain, a Palestinian health official, said the wounded were evacuated to a hospital. The Kamal Adwan hospital identified the two fatalities as eight-year-old Wesam Abed Allah and his six-year-old sister Hala. No Palestinian group blamed the IDF for the explosion.