The Nigerian man accused of trying to blow up a US flight bound for Detroit on Christmas Day allegedly got his orders from an al-Qaeda group in Yemen.
Umar Farouk Abdulmutallab was studying Arabic there, just a few months ago.
The director of the Arabic language institute he attended in Sanaa says he did not have any reservations about Abdulmutallab.
And his teacher describes him as a "gentleman and very polite ... not a fanatic or radical".
Al Jazeera's Omar al-Saleh reports.
Source: Al Jazeera