The Mumbai branch of India's National Investigation Agency (NIA) has launched a probe after receiving an email threatening to kill Prime Minister Narendra Modi with "20 kg RDX", a powerful explosive.
According to India's IANS news agency, apart from the prime minister, the person behind the threat also warned the NIA that they would harm millions of people by activating 20 sleeper cells.
"...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 email sent to the NIA reads.
The NIA and other intelligence agencies are trying to trace the sender by tracking the IP address and other information.
No other official information has been given out yet by the NIA.