Watch part two
Last summer, more than a dozen young Somali-American men disappeared from the US only to turn up as fighters in Somalia.
In the UK, officials reported the same phenomenon among London's Somali community.
The FBI described Shirwa Ahmed, a 27-year-old naturalised US citizen from Somalia, as the first American to carry out a suicide bombing.
He was a student at the University of Minnesota before blowing himself up in Somalia last October.
These revelations have rocked the expatriate Somali community to its core. Very connected to Somalia, their remittances keep millions of Somalis at home afloat.
Accusations of "terrorist links" have brought unwanted attention to the tens of thousands of Somali immigrants admitted to the US in the past two decades.
The largest community is in Minnesota, where they have been targeted for particular attention.
The FBI has interviewed dozens of Somali-Americans in Minneapolis and St. Paul, Minnesota and community members have reported harassment at airports and difficulties in completing banking transactions.
The Abubakar As-Saddique Islamic Center in St. Paul has received hate emails and phone calls for the past several months. Some have accused speakers at mosques of radicalising the youth.
Somalis say Ethiopia's invasion of their country in 2006 has inspired some of them to join the fight against occupation.
Why are young Somali-Americans getting radicalised and taking up arms? Is the chaos in Somalia causing a world wide security threat?
On Wednesday, Anand Naidoo sits in for Riz Khan and speaks with Mohamed Diini, a young Somali imam of a mosque in Columbus, Ohio; Hussein Samatar, a Somali community activist who heads the African Development Centre of Minneapolis; and Jennifer Cooke, who works on US-Africa policy at the Center for Strategic and International Studies in Washington, DC.
This episode of the Riz Khan show aired on Wednesday, March 18, 2009.