A United Nations official, on Saturday, called on the international community to investigate the outcomes of the ongoing Israeli military offensive on the Gaza Strip, mainly the killing of civilians.

The Israeli army has been carrying out an ongoing military air and ground offensive on the Gaza Strip for 22 successive days, killing more than 1,200 people and wounding some 5,200 others.

Gaza Health Ministry, ruled by Hamas, had said in an earlier statement sent to reporters that Israel killed 1,203 Palestinians, including 410 children, 108 women and 113 men at over 40 years old.

John Ging, UNRWA operations chief in the Gaza Strip told a news conference held at a school his organization runs in northern Gaza Strip that the world "should consider the international law and Geneva Fourth Convention."

The school, located in the northern Gaza Strip town of Beit Lahia, was shelled by Israeli army tanks earlier on Saturday, killing two children and wounded 14 others, including a woman in critical conditions.

Israel has targeted five UNRWA schools during the military offensive on the Gaza Strip, killing more than 60 civilians, who took refuge to 36 schools run by UNRWA allover the Gaza Strip after they fled their homes.

"Is the killing of civilians, mainly children (who took refuge) into these schools a crime of war or not?" asked Ging as he was speaking to reporters, adding "Civilians, mainly women and children who are paying the price of this war."

He added "today two children were killed in this school, and their mother's limps were cutoff. 14 civilians suffered from awful wounds, the world has to move and protect the Palestinians in the Gaza Strip."

Hundreds of houses were bombarded or shelled by the Israeli army air and ground forces, where 36 thousand Palestinians became homeless after their houses were either destroyed or they fled it due to the Israeli army incursions.

"There is no safe place in Gaza, even my house. Everyone is a subject to the shelling. Those people who are sheltering into these schools are normal people who asked protection and took refuge to these schools."

He added as he was referring to the Israeli shells "these shells are killing civilians and those who fired these shells should be taken to courts and must be sued by the law."