Attack on airbus 330 feared

Both officials at Air France and Brazilian air forces are strongly thinking of a possible explosion and attack on the airplane that was lost last Monday. Because pieces of the plane have been found as much as 300 kilometers from each other it seems the airplane exploded at cruising altitude. Also large amounts of kerosene have been found, larger then the amount that was on the plane.

While this could be true, I am then surprised no organization has been claiming the attack