GAZA CITY, Jan 6: Israeli shelling killed more than 40 Palestinians on Tuesday at a UN school where civilians had taken shelter, medical officials said, in carnage likely to boost international pressure on Israel to halt the Gaza offensive.

People cut down by shrapnel lay in pools of blood in the street. Witnesses said two shells exploded outside the school, killing at least 42 civilians and wounding dozens among people who had taken refuge there and residents of nearby buildings.

It took the Palestinian death toll in 11 days of violence to over 600 and prompted US President-elect Barack Obama to break his silence on the offensive, to say the loss of life among civilians was “a source of deep concern” for him.

A fourth day of a ground assault, launched after a week of air strikes, still failed to end Hamas rocket salvoes, which again caused damage and some injury in southern Israel.

A senior UN official in Gaza said 350 people had been sheltering at the Fakhora school and the United Nations regularly gave the Israeli army exact geographical coordinates of its facilities to try to keep them safe from attack.

Israeli Foreign Minister Tzipi Livni, asked by reporters about the deaths, said she was “not familiar” with the incident. “Unfortunately, (Hamas fighters) are hiding amongst civilians,” she alleged, adding that Israel was trying to avoid civilian casualties. The Israeli army released video which it said showed gunmen firing from another UN school in Gaza in 2007.

In a separate attack earlier in the day, three Palestinians were killed in an air strike on another school run by the United Nations Relief and Works Agency.

The deaths in Gaza, home to 1.5 million people, raised to 77 the number of Palestinian civilians killed on Tuesday alone, according to medical officials.

The spike in civilian casualties could prove to be a turning point in Israel’s “Operation Cast Lead”, launched on Dec 27 with the declared aim of removing the Hamas rocket threat.

In fighting on Tuesday, Israeli forces pushed into the southern town of Khan Younis and battled Hamas militants on the outskirts of the city of Gaza. Palestinian medical officials said four militants were killed.

According to the Palestinian Health Ministry in the Gaza Strip, at least 631 Palestinians have been killed and more than 2,700 wounded since Israel began its offensive.

Ten Israelis, including three civilians hit by rocket fire, have been killed in the conflict. At least five rockets landed in Israel on Tuesday, including one that hit the town of Gadera, 28km from Tel Aviv. A three-month-old baby was hurt.

In Gaza, an infant of similar age was among children killed.

Israeli military said it killed 130 militants since it began a ground assault on Saturday, a figure that suggested the total Palestinian death toll might be close to 750 and that bodies could still be on the battlefield.

Humanitarian crisis

Israel has denied there is a humanitarian crisis in Gaza, but the International Committee of the Red Cross stepped up pressure with a rare public statement.

“There is no doubt in my mind that we are dealing with a full-blown and major crisis in humanitarian terms. The situation for the people in Gaza is extreme and traumatic,” said Pierre Kraehenbuehl, ICRC director of operations.

He said ICRC staff in Gaza described the past night as “the most frightening to date” in the territory, where there is no power or water and food rations are severely limited.

Meanwhile, Israel’s Physicians for Human Rights group alleged that medical teams rescuing the wounded in Gaza were being attacked by Israeli forces inside the territory.

“Testimonies reveal that the IDF (Israeli military) is attacking medical teams that travel to rescue the wounded, including ambulances, doctors and medics in medical uniform,” PHR said in a statement, saying it had reports of 10 such cases.

Asked for comment, the Israeli military did not directly address the claim but insisted it “does all within its power to avoid injury to civilians” and accused the Hamas rulers of Gaza of using civilians as “human shields”.

PHR said it had received a phone call from Gaza’s Al Awda hospital saying medics were unable to head out to evacuate people wounded in Israeli strikes. “We cannot get the ambulances out because we are being fired at. The hospital is crying out for a coordination that will allow them to leave to evacuate the dead and wounded.”

Another caller, from the Red Crescent in Gaza, said: “We can’t get ambulances out because as soon as they leave they are fired at from Apache (assault helicopters.)”---Agencies