From a UN employee no less.
The photo first tweeted by Khulood Badawi (@KhuloodBadawi) and later by Diana Alzeer (@ManaraRam), allegedly depicting a Palestinian girl killed by an Israeli air strike yesterday, was proven to have originated in 2006 and to have had nothing at all to do with Israeli action. This photo is now the top tweet for #Gaza, with over 300 retweets. It is completely false.
Further research revealed that the photo was taken in 2006 by Reuters, and that the girl, initially thought to have been killed in an Israeli air strike, was injured by falling off a swing. When confronted with this information, Alzeer stated that the photo was taken last night and forwarded to the press that day.