An American student at an Ivy League university has been sentenced to 21 months in prison after threatening to kill Jewish students on campus and behead their babies.

Cornell student Patrick Dai, 22, pleaded guilty to posting a series of threatening antisemitic messages on a campus message board last year under several usernames, including “kill jews,” “Hamas soldier,” and “Sieg Heil”.

The Engineering student posted: “Watch out pig Jews. jihad is coming. nowhere is safe. your synagogue will become graveyards. your women will be raped and your children will be beheaded. glory to Allah”.

He also threatened to “shoot up” 104 West, a dining hall at the university in upstate New York that serves kosher food. He described Jews as “rats” who need to be eliminated and said he was planning to “bring an assault rifle to campus and shoot all you pig Jews”.

Dai also threatened to slit the throats of any Jewish men he saw on campus, to rape and kill Jewish women, and behead Jewish babies in front of their parents, the court heard.

"Every student has the right to pursue their education without fear of violence based on who they are, how they look, where they are from or how they worship," Assistant Attorney General Kristen Clarke of the Justice Department’s Civil Rights Division said.

"Antisemitic threats of violence, like the defendant’s vicious and graphic threats here, violate that right,” Clarke continued. “Today’s sentencing reaffirms that we will hold accountable those who violently threaten and intimidate others based on their religious practice or background”.

Before imposing a sentence, the court found that Dai’s actions constituted a hate crime. “The defendant’s threats terrorized the Cornell campus community for days and shattered the community’s sense of safety," said U.S. Attorney Carla B. Freedman.

Cornell has more Jewish students than any other Ivy League university – around 2,500. Following Dai’s messages, Rabbi Ari Weiss, the executive director of Cornell Hillel, said the Jewish community at the University heard the posts as “a call for our genocide”. Police were stationed at Cornell’s Jewish Centre.

Jewish students at Cornell University have had death threats levelled against them (Photo: Getty)

Rabbi Silberstein, from Cornell Chabad, told the JC at the time: “These antisemitic posts were designed to sow panic and hysteria, which they, unfortunately, succeeded at generating. The fact is that by showing panic and fear we play into their schemes”. He said that although “the administration should respond to this with the fullest seriousness… the rest of us should take it for what it is - a cowardly threat and nothing more”.

Patrick Dai, who was a junior at Cornell when he was arrested after sending the antisemitic messages, was diagnosed with autism after the incident – something his lawyer said explains his crime.

“He believed, wrongly, that the posts would prompt a ‘blowback’ against what he perceived as anti-Israel media coverage and pro-Hamas sentiment on campus,” Peebles, Dai’s lawyer, wrote in court papers last month. “Patrick’s flawed logic is a result of his autism”.

“He was depressed, he struggled with autism, he had not been diagnosed yet, and he had a breakdown and came up with this idea to do these posts,” she said.

Prosecutors argued that “the defendant terrorised a campus community for days and horrified the nation at a very volatile time,” and that his autism was not a defence.