The UN's Secretary General says he is "appalled" by an attack on a school in Gaza which has killed at least 16 people.
Ban Ki-Moon says he "strongly condemns" the shelling of the compound housing the school, which was being used as a UN shelter.
Women, children and three UN staff were among the dead.
One hospital spokesman Hakim el Masri says hundreds of people were inside the school when it was hit by Israeli tank shells.
The UN chief again demanded that Israel and Hamas abide by international humanitarian law during their conflict and respect “the sanctity of civilian life, the inviolability of UN premises” and protect humanitarian workers.
He said in a statement in Erbil, Iraq, which was released at UN headquarters, that the “circumstances are still unclear”.
“Today’s attack underscores the imperative for the killing to stop – and to stop now,” Mr Ban said.
Mr Ban said UN staff are attempting to arrange ``a humanitarian pause in the hostilities so that civilians could be evacuated''.