Sindh Rangers on Friday foiled a big terror plot in the metropolis after recovering huge quantity of explosives and arrested four accused from a passenger coach coming from Punjab to the coastal city. Rangers spokesman said that the Rangers raided a bus in Kot Sabzal, Sindh-Punjab border area, and recovered 50 kilogram explosives and 1900 detonators and arrested four accused including two drivers and two others. He informed further that the bus was coming to Karachi from Sargodha.