A 40-minute video released online earlier this year, titled Minnesota’s Martyrs: The Path to Paradise, promised would-be recruits a glamorous new life.

It followed three young Minnesotans – Dahir Gure, Muhammad Al Amriki and Mohamud Hassan – from their ordinary lives to Somali training camps. “If you guys only knew how much fun we have over here,” Gure told viewers at one stage. “This is the real Disneyland”.

Friends say Hassan was previously an unremarkable engineering student who spent much of his time caring for his 90-year-old grandmother.

“They are being radicalised, and that’s something we are attempting to thwart with the support of the greater Somali community, who are absolutely appalled,” said Mr Loven.

Abdirizak Bihi, a director of the Somali Education and Social Advocacy Centre, has worked to assist these efforts since losing his nephew, Burhan Hassan, to the recruiters. “We would never have guessed that our kids had been brainwashed and recruited,” he said.

Eight Minnesota men have been jailed in recent years as part of Operation Rhino, the FBI’s inquiry into the so-called “jihadist pipeline” to Somalia.

Recruiters from al-Shabaab are targeting disaffected young men in the “Twin Cities” of Minneapolis and St Paul, which are blighted by gangs and high youth unemployment.