This happened soon after Egypt opened up the Rafah crossing with Gaza for only the fourth time since October.
This alarmed Hamas leaders, who did not want Egypt to blame them for the bomb and close the crossing early.
So Moussa Abu Marzouk, Hamas leader who lives in Cairo, blamed Israel for the bomb, saying that they are the ones who gain from killing Egyptian soldiers because attacks like that often prompts Egypt to close the crossings. "Malicious hands are behind every terrorist incident in the Sinai," he wrote on his Facebook page. "I do not rule out here the hands of the Zionists for these acts, starting from the death of Egyptian soldiers in the operation in Rafah In August 2012 until the attack today."
He claimed that Hamas could not have been behind the attack saying (from personal knowledge, no doubt) that terror attacks take time to plan and since Egypt only announced the opening of the crossing on Saturday, there wasn't enough time for Hamas to plan and implement such an attack.
It is funny seeing Hamas bounce back and forth between insulting Egypt for its anti-Hamas stance and begging Egypt for mercy.