A new Salafist group, as noted in the article, apparently did it, but the government is ultimately responsible. Many people have pointed out the oh-so-coincidental timing and are wondering if it wasn't a false flag. Was probably pretty obvious to the Pres and his security detail.
Egypt to hold parliamentary election in 2 phases starting Oct 18-19 (Reuters)
from the article: With rocket launches at Sderot, Hamas shows it makes the rules