Two armed men who made violent threats against a synagogue in New York have been arrested after the Community Security Trust (CST) used Twitter to foil their plan.

After a tip-off by the British-Jewish security group, Christopher Brown, 21, and Matthew Mahrer, 22 were taken into custody in New York late on Friday night. They were found carrying a gun, a military-style knife and a swastika armband.

The pair were charged with criminal possession of a loaded firearm with the intent to use it unlawfully against another person.

“We regularly scour the internet for threats against Jews and found a string of tweets from an anonymous account threatening to imminently attack an unnamed synagogue,” said CST policy director David Rich.

“They didn’t specify a location but our initial investigation suggested it was based on the east coast of America and we shared this with our US partners. Within a few hours, two suspects had been identified, located and arrested.”

FBI rposter eleased Christopher Brown

Christopher Brown pictured on a New York Police poster

Manhattan district attorney Alvin Bragg said a “potential tragedy” had been averted by the CST’s intelligence. “My office will now pursue justice in this case with the full resources of our counter-terrorism programme.”

“It could have been a Pittsburgh Tree of Life situation,” said Mitchell Silber, the executive director of New York’s Community Security Initiative, one of the organisations tipped off by the CST.

In the early hours of last Friday, Brown had declared on Twitter that he was “gonna ask a priest if I should become a husband or shoot up a synagogue and die.” Later that day, he added: “This time I’m really gonna do it.”

In his subsequent statement to the police, he said he “had a sick personality” and was “going to be a coward.”

When police searched Mahrer’s Upper West Side apartment they discovered a loaded gun and a bulletproof vest. At his bail hearing, Mahrer’s lawyer said he was the Jewish grandson of a Holocaust survivor.

Police said he had a history of mental illness. It has also been reported that he had been living in homeless shelters before moving in with his parents last year.

Commenting on the CST’s tip-off, its chief executive Mark Gardner explained that a lot of the work it does to protect Jews goes on behind the scenes.

“This case gives a flavour of the expert research and investigations that underpins it,” he said.

“We are thankful that on this occasion we were able to share this information in real time with our partners in the US to prevent what could have been serious attack.”