Lewthwaite, 29, who grew up in Aylesbury, is not known to the law-enforcement agencies as a combatant. She is, however, seen as a facilitator and is wanted in connection with a plot to blow up a shopping centre and hotels in Mombasa two years ago. She is believed still to be engaged in clandestine activity.
The largest group of foreign fighters is said to have come from various parts of the US including the states of Kansas, Maine, and Illinois, and the city of Minneapolis. According to evidence before the US Congress, a number of mosques in the cities of Minneapolis and St Paul were running recruitment programmes and sending volunteers to fight in Somalia.