At least 51 civilians in the Gaza Strip have been killed in Israeli air strikes since Saturday, according to a tally by a UN aid agency.
"It is likely to be conservative and it is certainly rising," UNRWA spokesman Christopher Gunness said today.
He said the estimate was based on visits by UNRWA officials to hospitals and medical centres across the Gaza Strip.
Palestinian officials have said more than 300 people, including scores of civilians, have been killed in the Hamas-controlled territory since the Israeli offensive began.
Reuters