narendra modi
Prime Minister Narendra ModiReuters

Mathura Police have booked a youth and detained two others in connection with a message, "threatening to kill the Prime Minister", circulating on WhatsApp and social media days ahead of Narendra Modi's Mathura visit on Monday.

The prime accused has been identified as Ramveer Singh, who is on the run at present, but police are questioning the detainees, including the accused's brother who admitted that the former was sending those messages.

"Ramveer's brother Laxman Singh has been detained and is being interrogated. Ramveer had sent the message to some people, including media persons," SSP Rakesh Singh said, according to The Indian Express.

According to police, Ramveer had allegedly sent the message to some media persons on 20 May. As the incident occurred days ahead of Modi's Mathura visit, the police put Ramveer's number under surveillance.

Ramveer, a resident of Naavali village, is said to have committed similar crimes earlier, said District Magistrate Rajesh Kumar. "A case under relevant Sections of the IPC will be registered against him," he further said.

Modi will address a rally in Jan Sangh ideologue Deen Dayal Upadhyay's birthplace Chandrabhan village on Monday.