Growing threat Chief’s killing comes as terror group gains ground in Africa

t was one of Ayman al-Zawahiri’s last victories. Just over a week before the al-Qaida leader was killed in Kabul by missiles fired from a US drone, militants from the organisation’s biggest affiliate in sub-Saharan Africa attacked the most important military base in Mali. The tactics of the attack were familiar – suicide bombers blowing a gap in defences to allow gunmen to reach