As in the case of Spanish bombings first the explosives must be smuggled into India and then they needed to get access to the Mumbai rail system. They must also know precisely the timing of the trains and their running on the lines. Then they needed to have time to place the explosives on the train either in the under belly of the chassis or on the floor of the compartments. This means they needed to have access to the secure Mumbai rail system. And then the charges had to be precise. Timing sho...
