Senior Palestinian official Hanan Ashrawi said the video showed what Palestinians have long alleged regarding the actions of Israeli occupation forces on the Gaza border, "but nobody has been listening".
Israel's military said the incident "apparently" took place several months ago and that it was investigating.
According to a statement, NGO Monitor "has documented concerns that nongovernmental organisations like NRC do little to mitigate the risks of aid diversion when operating in conflict zones and areas controlled by terrorist groups", adding that "NRC's statements criticizing 'counter-terrorism measures' created to prevent Hamas and other Palestinian terrorist factions from commandeering materials and funds ... are highly problematic".
"Wow. What a video! Yes!"
Ayman Odeh, a leading Arab legislator in the Israeli parliament, denounced the video, saying it "horrifies the soul".
Israeli Public Security Minister Gilad Erdan downplayed the actions of those in the video that began to spread widely on Monday night.
Defense Minister Avigdor Lieberman told reporters on Tuesday that Murtaja had been on the Hamas payroll since 2011 and held a rank similar to captain. David Keyes, a spokesman for Israeli Prime Minister Benjamin Netanyahu, tweeted, "Turns out the "photographer" killed in Gaza was an officer in Hamas, a terrorist org that seeks Israel's destruction".
Israeli Education Minister Naftali Bennett also criticised the storm of negative reactions that has followed the emergence of the video. The video was recorded on December 22 in the area of Kissufim near the Gaza Strip, it said.
"We have been complaining about this, but unfortunately nobody believes it unless an Israeli source documents it", Ashrawi told AFP. It comes as Palestinians were mourning the deaths of 29 people over the last two weeks, shot by Israeli forces during renewed protests along the fence that divides Israel and Gaza.
Israeli media has reported that "the orders received from the [army's] General Staff" allow soldiers to open fire in three scenarios: "a life-threatening situation, if he detects damage to state infrastructure and if he spots key instigators" - even those unarmed and 100 metres from the fence.
Lieberman accused Hamas, the militant group that controls Gaza, of using the media, as well as ambulances and medical patients, as cover to carry out attacks.
The video, Jubran went on to stress, "reflects the fact that Palestinians are regularly targeted [by Israeli soldiers] for entertainment".
But opinion roughly divided along predictable lines, with some who oppose Israel's policies toward the Palestinians expressing shock and others who are more supportive defending the shooting and dismissing the soldiers' cheers as an nearly natural release of tension.
Russell Crowe: The Art of Divorce - AU0822
But there was also some top-notch Australian art on show from artists such as Sidney Nolan and Margaret Olley. However, film memorabilia drew some of the greatest attention both before and during the auction.