The United States officials have charged 14 people with providing money, personnel and services to the Somali militant group al-Shabab. The charges stem from four separate indictments in the US States of Minnesota, Alabama and California.Concerns about al-Shabab have grown after the group carried out a bomb attack in Uganda.The group is linked to al-Queda. The indictments follow a two year investigation by the FBI into claims that American of Somali descent are joining al-Shabab. In Minnesota, several suspects have already been arrested.In two separate indictments, prosecutors charged Shafik Hammami, a former resident of the US state of Alabama, and Jehad Serwan Mostafa, formerly of California, with providing material support to al-Shabab.