The Mumbai branch of National Investigation Agency has received an email threatening to harm Prime Minister Narendra Modi as the sender claimed to have "20 kg RDX".The threat mail mentions that he is ready to harm millions of people along with the Prime Minister."...I have met with some terrorists, they are going to help with rdx, I am happy that I have got bombs very easily and now I will blast everywhere... I have planned it, 20 sleeper cells will be activated and millions of people will be killed..."The NIA and other intelligence agencies were trying to trace the sender.Sources close to the development have said that they were tracking the IP address and were gathering other information about the sender.As of now, the NIA has not given any official information in this respect.