Gazan authorities said Israeli forces shelled a shelter at a UN-run school, killing at least 15 people, as the Palestinian death toll in the conflict reached 808 and attempts at a truce remained elusive.

United Nations Secretary-General Ban Ki-moon expressed horror at the Thursday attack on the school at Beit Hanoun in the northern Gaza strip. "Many have been killed - including women and children, as well as UN staff," he said. "Circumstances are still unclear. I strongly condemn this act."

Ban later arrived in Cairo, where he was expected to meet US Secretary of State John Kerry, who has been working the telephones to try to broker a truce.

Kerry's spokesman said the school attack "underscores the need to end the violence".

But there was no sign of progress on securing a cease-fire in his four days in the region. "Gaps remain between the parties," a senior US official said, adding that Kerry would not stay "for an indefinite amount of time".

The Israeli military said it was investigating the school incident.

Pools of blood lay on the ground and on students' desks in the courtyard of the school near the apparent impact mark of the shell, according to a Reuters photographer at the scene.

Scores of crying families who had been living in the school ran with their children to a hospital a few hundred meters away where the victims were being treated. Laila Al-Shinbari, a woman who was at the school when it was shelled, told Reuters that families had gathered in the courtyard expecting to be evacuated shortly in a Red Cross convoy.

"All of us sat in one place when suddenly four shells landed on our heads. ... Bodies were on the ground, (there was) blood and screams. My son is dead, and all my relatives are wounded including my other kids," she wept.

Reuters - AP

(China Daily 07/26/2014 page12)