The shoe of a child is seen on blood stains in a classroom at the UN school that was hit earlier today by an Israeli strike in Beit Lahia, northern Gaza Strip on January 17, 2009. United Nations officials today demanded an investigation into a new Israeli strike on a UN-run school in Gaza, which killed a woman and a child in the fourth such attack during its war on Hamas. AFP PHOTO / MAHMUD HAMS (Photo credit should read MAHMUD HAMS/AFP/Getty Images)