NEW : The State Department says withdrawal of personnel is in response to a specific threat . Depending on when a new crescent moon is seen , the Muslim holy month could end Wednesday or Thursday . Security steps increase in Yemen due to intercepted al Qaeda message , other threats . Comment: `` Do something , '' ordered a message from al Qaeda 's leader to his Yemeni deputy .
NEW : The State Department says withdrawal of personnel is in response to a specific threat . Security steps increase in Yemen due to intercepted al Qaeda message , other threats . Comment: `` Do something , '' ordered a message from al Qaeda 's leader to his Yemeni deputy .