At least 20 young American men of Somali background secretly left their homes in Minneapolis to return to Somalia and fight alongside a militant group called al-Shabab, with links to al-Qaeda.They wanted to resist an US-backed invasion of their homeland by neighbouring Ethiopia.Among them was Shirwa Ahmed who became the first known American suicide bomber.Al-Shabab was on Washington's list of terror organisations, so all the young men who went to fight in Somalia were classified as terrorists.The impact on the Somali community in Minneapolis was devastating and they are still feeling the repercussions two years later.