 Complete the following phrase:  A Semtex bomb was used in the Pan Am Flight 103 known also as the Lockerbie bombing in 1988. A belt laden with of RDX explosives tucked under the dress of the assassin was used in the assassination of former Indian prime minister Rajiv Gandhi in 1991. The 1993 Bombay bombings used RDX placed into several vehicles as bombs. RDX was the main component used for the 2006 Mumbai train bombings and the Jaipur bombings in 2008. It also is believed to be the explosive used in the 