Israeli shelling on a UN school being used as a shelter in the Gaza Strip has killed 23 people and injured scores of others, Palestinian medics says.

Wednesday’s shelling hit the school in Jabaliya refugee camp, emergency services spokesman Ashraf al-Qudra said, on the 23rd day of Israel's military campaign against the Palestinian coastal enclave.

An official for the UN's Palestinian refugee agency, UNRWA, told the AFP news agency that the strike hit a bathroom and two classrooms inside the girls' school.

Al Jazeera's Imtiaz Tyab, reporting from Gaza's Kamal Adwan hospital, where scores of injured were taken, said there were more than 90 injured.

"Looking around me I can see some with have what appears to be shrapnel wounds and some with far more serious wounds," he said.

He said people there did not know why Israel had hit the shelter, adding that the attack caused panic among people living in different UN-run shelters.

"As we were driving to the hospital, we saw families with many children leaving other UN schools. They feel insecure. There seem to be no safe shelter for them, not even in UN schools," our correspondent said.

Almost 15,000 Palestinians were seeking shelter in 83 UNRWA schools, according to UN refugee agency.

The army had begun heavy tank shelling in the area a couple of hours prior to the incident.

The shelling brought Wednesday morning's death toll to at least 35, in a conflict that has killed more than 1,263 Palestinians, according to Qudra's figures.

(Aljazeera)