Tel Aviv  -  Palestinian militants fired mortar shells from the UN school in northern Gaza which was shelled by Israel and which killed more than 46 civilians, a military spokesman in Tel Aviv charged.

He said Israeli ground troops stationed on the outskirts of the Jabaliya refugee camp responded by firing mortar shells in the direction of the militants.

"This is not the first time that Palestinian militants have fired from within UN schools," he said.

Local residents had earlier said Palestinian militants had indeed fired mortar shells at the Israel ground troops stationed outside Jabaliya, but from near the school, not from inside.

UNWRA staff, the UN agency running the school, in turn said the building was clearly marked with a blue UN flag and that it had provided Israel with the GPS coordinates of all its schools and shelters in Gaza. (dpa)