Six Palestinians suspected of collaborating with Israel have been executed in the past two days by Hamas security officers in the fighting zone in Jabalya, Ynet has learned.Which means that the number of Arabs killed by Hamas since the war started is at least 50 (8 from 2008).
Among the alleged collaborators were three brothers, one of whom attempted before his arrest to swallow a cell phone's SIM (Subscriber Identity Module) card, which is believed to have documented his conversations with Israeli security officials.
In addition to the siblings, three other Palestinians were executed shortly after being seized on suspicion of collaborating with Israel and guiding the IDF forces, particularly Air Force warplanes, before the strikes.
This is not counting the likely deaths from Hamas firing at IDF soldiers. (I recall a story a few days ago about 10 students killed in crossfire, sorry I did not bookmark it. If someone has that story please ping me.) It also doesn't count the two young sisters killed by an errant Qassam the day before Operation Cast Lead started.
It is not likely that you will find any newspapers keeping a count of the number of Arabs killed by Hamas, however. It is extremely likely that they are all included in the incessant counts of people supposedly killed by Israel.
My 2009 PalArab self-death count is now at 43 (one of whom was in the West Bank.) These numbers are necessarily mostly from Israeli sources, as the Palestinian Arab media is very reluctant to speak about these except in very general terms, so I have had to loosen up my rules a little in deciding who is included. (This YNet article included their own verification, the earlier JPost article on 35 "collaborator" deaths didn't, which bothers me.) In reality, the numbers are probably higher.
UPDATE: I may have double-counted some; I'm adjusting accordingly.