Witnesses said that they used silencers and used only one for the attack . Many bloody conflicts plague the impoverished country . Shiite rebels have long fought for independence , and Al Qaeda has a key hub in Yemen . With the help of drone strikes allegedly carried out by the CIA , Yemen 's military put militants in the country 's tribal region on retreat last year , but AQAP regularly carries out terrorist attacks on soldiers and officials . Terrorist attacks in Yemen occur regularly .
Witnesses said that they used silencers and used only one for the attack . Many bloody conflicts plague the impoverished country . Shiite rebels have long fought for independence , and Al Qaeda has a key hub in Yemen . Terrorist attacks in Yemen occur regularly .