International condemnation continues to mount towards Israel over its bombardment of the Gaza Strip, as the death toll rapidly rises following two strikes on Palestinian civilian areas on Wednesday.

An Israeli airstrike blew through a UN school in the Jabaliya refugee camp in Gaza early Wednesday morning, killing 20 people and wounding more than 90, according to the Palestinian Health Ministry. The school was being used as a shelter for more than 3,000 Palestinians who were seeking refuge after fleeing their homes.

Israel denied that they had targeted the school but had just “responded by firing toward the origins of the fire,” according to a military spokesperson.

This is the sixth strike on a UN facility sheltering Palestinians during the current conflict. Last week, Israel denied responsibility for an attack on a UN school that killed 16 people, mostly women and children.

Wednesday’s strike provoked outrage from the UN, which condemned the attacks on civilian populations seeking safety in an unusually strong manner.

"Last night, children were killed as they slept next to their parents on the floor of a classroom in a UN designated shelter in Gaza," Chris Gunness, the spokesman for the United Nations Relief and Work Agency for Palestinian refugees, said in a statement. "Children killed in their sleep; this is an affront to all of us, a source of universal shame. Today the world stands disgraced.

"We have moved beyond the humanitarian realm. We are overwhelmed...There are tens of thousands of people in the streets in Gaza without food, without water, without shelter. That's why we call on the international community to take deliberate political action to end this ongoing carnage."

According to Gunness, the UN had told Israel of the school’s location 17 times and repeatedly warned them not to strike it.

The Israeli military announced a four-hour humanitarian “lull” on Wednesday afternoon but cautioned that it would not apply to areas that soldiers were already operating in and told residents not to return to their homes.

The Israeli military also promised it would “respond to any attempt to exploit this window to harm Israeli civilians.”

Hamas rejected the ceasefire because it did not include much of the region, such as the border areas being used to evacuate the injured, saying in a statement that it was “just for media consumption and has no value.”

Despite the humanitarian ceasefire announcement, local reports emerged Wednesday evening that Israeli airstrikes hit a market and multiple homes in the neighborhood of Shujaiya at around 6pm. At least 33 people were killed, 17 of whom were in the market, and 200 injured. According to the Gaza Health Ministry, those dead included a local journalist and two paramedics.

According to initial reports on the scene, the shelling occurred as medics were still taking the dead and wounded to Al-Shifa hospital.

The journalist was named as Rami Rayan, a photographer for the Palestinian Network for Journalism and Media.

Image for journalist Rami Rayan, killed moments ago in Israeli airstrike on

— Middle East Monitor (@MiddleEastMnt)

July 30, 2014

I don't know what just happened, but at Shifa we received +100 injuries within minutes. it's a massacre. — Belal - Gaza (@Belalmd12)July 30, 2014

The attacks come after Israel significantly escalated its operation on Tuesday, hitting the home of Hamas’ deputy chief in addition to Gaza’s sole power plant, forcing it to shut down.

The power plant attack has drastically worsened the humanitarian crisis, as it effectively makes it impossible for Gaza’s 1.8 million residents to receive any clean water or electricity.

The mounting humanitarian crisis in Gaza has not just provoked condemnation from the UN, but has also prompted five countries to pull their ambassadors to Israel from the country in protest. Today, El Salvador became the latest country to pull their envoy from Tel Aviv, following Brazil, Chile, Ecuador and Peru.

"Chile notes with great concern and dismay that such military operations, which at this stage of development are subject to a collective punishment against the Palestinian civilian population in Gaza, do not respect fundamental rules of international humanitarian law,” said Chile’s foreign ambassador in a statement explaining the decision.