Umar Abdulmutallab, the Nigerian national who tried unsuccessfully to blow up a US airliner on Christmas day, has caused a great deal of concern for Yemeni authorities.
Mutallab is suspected to have been radicalised while being in Yemen and the possilbe presence of al-Qaeda in the country has added to the worries. Yemeni authorities have decided to increase security measures by sending forces to several provinces throughout the country and staging a number of anti-terrorist training exercises.
Troops also performed mock raids on Saturday in the outskirts of Sanaa, the capital of Yemen.
Al Jazeera's Mohammed Vall reports.
Source: Al Jazeera