Looking to increase security, Israel dropped leaflets last week warning residents to stay at least 1,000 feet from the border or risk being shot.
In Sderot, Purim holiday fun masks stresses of rocket attacks from Gaza militants.
The US pledged $900 million, but said the money would not go to Hamas.
Among the scores of Palestinian prisoners who Hamas wants freed in exchange for Israeli Sgt. Gilad Shalit is Marwan Barghouti, the most popular man in Fatah.