Man charged with threatening to kill Indian-American presidential candidate Vivek Ramaswamy

A 30-year-old man has been arrested and charged in connection with death threats aimed at Indian-American Republican presidential candidate Vivek Ramaswamy and his campaign event attendees, the US attorney's office in New Hampshire has said.

The attorney's office on Monday said Tyler Anderson of Dover in New Hampshire was arrested on Saturday and charged with transmitting in interstate commerce a threat to injure Ramaswamy, a 38-year-old biotech entrepreneur.

According to an FBI affidavit, the Ramaswamy campaign sent a text message on Friday to notify voters, including Anderson, about an upcoming campaign event in Portsmouth.

Anderson allegedly responded to the message: Great, another opportunity for me to blow his brains out!

Ramaswamy's staff reported the threatening text messages to authorities, the FBI affidavit said.

Law enforcement officials searched Anderson's residence on Saturday, arrested him, and seized his phone and firearms.

While searching Anderson's phone, the affidavit says, authorities discovered the texts to Ramaswamy in a deleted folder and found additional threatening messages to another candidate.

Subsequent texts were referring to a mass shooting and intentions to defile a corpse.

Anderson admitted to sending the text messages to Ramaswamy and confirmed that he sent threatening texts to other campaigns, according to the affidavit.

A businessman and a Republican presidential candidate, Ramaswamy went on to hold the event in Portsmouth on Monday.

Threats of violence against politicians are up, Forbes cited a recent University of Massachusetts-Amherst survey of nearly 300 former members of Congress as suggesting.

The survey found 47 per cent reported receiving threats while in Congress, with those who were first elected more recently experiencing a higher number of threats than those first elected earlier.

The numbers were split fairly evenly across party lines, but women and people of colour reported receiving threats at a much higher rate of 69 per cent, Forbes reported.