CNN declined . Officials say that in early 2009 , group set off from Hamburg for tribal areas of Pakistan . Police detained a group member before he left ; 2 were arrested after arriving in Pakistan . Agencies think other members of the group remain in the Afghan / Pakistan border area . Border area group is linked to incidents that prompted concern for U.S. citizens living in Europe .
Officials say that in early 2009 , group set off from Hamburg for tribal areas of Pakistan . Police detained a group member before he left ; 2 were arrested after arriving in Pakistan . Agencies think other members of the group remain in the Afghan / Pakistan border area . Border area group is linked to incidents that prompted concern for U.S. citizens living in Europe .