The National Investigation Agency (NIA) on Tuesday filed a supplementary charge-sheet in the special court here in a case against four Jaish-e-Mohammad (JeM) operatives, all residents of Pulwama in Jammu and Kashmir.The case was filed under Sections 120B, 121A of the Indian Penal Code (IPC), Section 18, 19, 20, 38 and 39 of UA(P) Act and Sections 4 and 5 of Explosive Substances Act against Sajjad Ahmad Khan, Bilal Ahmad Mir, Ishfaq Ahmad Bhat and Mehraj-ud-Din Chopan, reads a statement.The case pertains to a criminal conspiracy hatched by the senior commanders of JeM to carry out terror attacks in different parts of India including Delhi-NCR. Investigation has established that the accused persons are members of proscribed terrorist organisation JeM, who were planning to carry out terrorist attacks and propagating the activities of JeM.The slain terrorist Mudassir Ahmad Khan was the mastermind behind this conspiracy. He was one of the main conspirators in Pulwama terror attack as well .