With the proper type of detonator, an explosion of a fuel-air mixture can produce an overpressure of 300 psi. Within the detonation cloud, blast shelters can be damaged and their occupants killed. Iraq may have had access to FAE technology from West Germany or the Soviet Union. While some authorities say there is no defense against FAE weapons, an expedient defense actually has been demonstrated in tests conducted at White Sands missile range and elsewhere. The principle is to ignite the gas and cause a deflagration before the fuel-air mixture can be detonated.
Many different devices are conceivable.
An 18-inch dead tumbleweed tied with a string to the wire handle of a fuse lighter has been used with some success.