Who killed 25 Egyptian police in the Sinai?

Rafah is a town in the Sinai peninsula, on the border between Egypt and Israel.  Yesterday (apparently) near that town a group of armed men stopped two buses carrying unarmed Egyptian police.  They ordered the police off the bus and proceeded to shoot them all, killing 25.

Hard to know who would benefit by killing 25 Egyptian policemen but it's a fair bet the killers were members of the Muslim Brotherhood, which has been exchanging fire with Egyptian government forces at all levels for a week or so now.

Okay, muslims killing other muslims in the Middle East isn't news.  Here's the part that makes the story unusual:  A Palestinian group called the Popular Resistance Committees sent a message to a Gaza news agency claiming that the attack was planned and "implemented" by...Israel.

Ya gotta wonder:  Do these folks actually believe the bullshit they spout, or do they cynically push the propaganda thinking the West is stupid enough to believe it?

Hard to decide, eh?