The IDF had posted this aerial video, filmed in October 2007, on YouTube last Thursday. They cite it as evidence that Hamas has previously used a school as a location to fire mortar shells.

They then issued this explanation from spokesperson Brig. General Avi Benayahu on Tuesday.

Husam El-Nounou is a resident of Gaza City. He works for an NGO that deals with mental illness sufferers.  

This is a civilian massacre going under the false allegation of the use of a school for a military operation. Even supposing there was an operation taking place in that school, they don't need to kill everybody in the surrounding area. And I don't believe the Palestinian resistance would use public places to target attackers anyway. I wouldn't be surprised if the video of militants firing from the school are fabricated. The Israeli Army would do that to justify their actions.

The reason I believe that is because this has happened so many times, in so many places; for example in Lebanon, when 'mistakes' were admitted later. Not that this incident necessarily is a mistake - personally I believe it could be a deliberate attempt to create a sense of panic, a way to force people into fleeing to Egypt. Although that's not allowed at present, if conditions worsen it might come to it.

Now they're mobilising more soldiers for the ground attack we're getting very scared. I expect a huge, huge massacre. Thousands of people will be killed. Gazans don't have the means of resistance. There will be street wars yes, but Palestinian civilians will end up paying the highest price."

Amatzia Baram is a historian specialised in Middle Eastern conflict. He teaches at the University of Haifa, Israel.

Hamas has been using this tactic of hiding and attacking from civilian areas for years. We have the proof in photos. And in any case, everybody knows that Hamas thrives on dead civilians. For Hamas, killing either Israeli or Palestinian civilians is a win-win situation, because of the international support they gain from the latter. For Israel it's lose-lose. Out of the first 400 Palestinians killed, only 50 of them were civilians. That's because the army was careful to telephone private properties before bombings [the death count in Gaza is now 680 according to Palestinian medical services. Some 300 of these are civilians, according to Palestinian and UN figures].

The Israeli army has the option of saying this was a mistake. But I'm inclined to believe that this was nothing of a mistake. There were two Hamas members killed in the school - we know that because their names [Imad Abu Askar and Hasan Abu Askar] were on the victims' list.

It would be nice to get rid of Hamas altogether. But that's not the aim of this war. Firstly, because casualties in Israeli soldiers and Palestinian civilians would be very high. Secondly, because Israel doesn't want to have to take control of Gaza if they destroy Hamas. That's what would end up happening because Abu Mazen [Mahmoud Abbas, Palestinian Authority President] wouldn't have the control to be able to do it. Israel simply wants to punish Hamas and demonstrate the cost of continuing to bomb and shell Israeli settlements. We don't want to 'win' a war. We're just waiting for Hamas to reach a conclusion to finish the war by agreeing to a few small conditions. But for now, we're in deadlock."