GAZA CITY, Gaza Strip -- There was no escaping the war Thursday -- not for the Palestinians who sought shelter in a United Nations school in the northern Gaza strip.
The school was hit by shells -- the Palestinians say they were fired by Israeli tanks. The Israeli military suggested it might have been Hamas rockets. Palestinian officials say at least 15 people were killed.
CBS News' Barry Petersen was at the scene of a hospital that received the victims. There was only one question amid the chaos, he reports - How does this kind of war make sense?
Ibrahim Shin-Barry lost three cousins; and his son wounded.
"There was no warning. No warning," he told Petersen.
Eight days ago, residents took shelter at the U.N. school as a safe haven. The U.N. said it gave GPS coordinates of the school to both Hamas and the Israelis to help arrange a humanitarian cease fire for an evacuation.
And then the shells started coming down.
"They killed our son," said one woman. "Where do we go now."
Meanwhile CBS News ' Don Dahler reported how Israeli military continued search for tunnels they say Hamas uses to smuggle weapons and explosives, and to launch raids.
U.N. Secretary-General Ban Ki-moon angrily denounced the attack, saying the killing must "stop now." But the frantic diplomatic efforts spanning the region were running into a brick wall: Israel demands that Hamas stop firing rockets without conditions, while Gaza's Islamic militant rulers insist the seven-year Israeli-Egyptian blockade of the territory must end first.
"Many have been killed - including women and children, as well as U.N. staff," Ban said in a statement, though he did not elaborate and a later U.N. communique made no mention of humanitarian workers being among the casualties.
In the aftermath of the attack, a child's sandal decorated with a yellow flower lay in a puddle of blood, while sheep and cattle belonging to those seeking shelter grazed in the grass nearby. A large scorch mark scarred the spot where one of the shells hit. Dozens of wounded, including many children, were wheeled into a nearby hospital as sirens wailed.
The U.N. said it had been trying to achieve a humanitarian pause in the fighting to allow the evacuation of civilians from the area.
Kamel al-Kafarne, who was in the school, said people were boarding buses when three tank shells hit.
"We were about to get out of the school, then they hit the school. They kept on shelling it," he said.
It was the fourth time a U.N. facility has been hit in Gaza fighting since the Israeli operation began on July 8. UNRWA, the U.N's Palestinian refugee agency, has said it discovered dozens of Hamas rockets hidden inside two vacant schools, but U.N. spokesman Farhan Haq said the school hit Thursday in the northern town of Beit Hanoun was not one of them.
The U.N. has also expressed alarm that rockets found in the schools have gone missing after they were turned over to local authorities in Gaza. "Those responsible are turning schools into potential military targets, and endangering the lives of innocent children," U.N. staff and anyone seeking shelter there, a U.N. statement said.
Fighting was fierce across Gaza Thursday, and at least 119 Palestinians were killed, making it the bloodiest day of the 17-day war. That raised the overall Palestinian death toll to at least 803, Gaza health official Ashraf al-Kidra said. Israel has lost 32 soldiers, all since July 17, when it widened its air campaign into a full-scale ground war. Two Israeli civilians and a Thai worker in Israel have also been killed by rocket or mortar fire.