In both Nairobi and Dar es Salaam, Mohammed Odeh supervised construction of two very large, destructive devices. The Nairobi bomb was made of 400 to 500 cylinders of TNT (about the size of drink cans), ammonium nitrate, aluminum powder, and detonating cord. The explosives were packed into twenty specially designed wooden crates that were sealed and then placed in the bed of the trucks. Muhsin Musa Matwalli Atwah ran a wire from the bomb to a set of batteries in the back of the truck cab and then to a detonator switch beneath the dashboard. The Dar es Salaam bomb was of slightly different construction: the TNT was attached to fifteen oxygen tanks and gas canisters, and was surrounded with four bags of ammonium nitrate fertilizer and some sandbags to tamp and direct the blast.