Rise of Isis means Boko Haram’s decline is no cause for celebration

Analysis: reported death of Boko Haram's leader will increase the influence of Islamic State affiliates

For more than a decade, Nigerian security services and their international supporters have struggled to end Boko Haram's brutal reign of terror over north-eastern Nigeria.

But few observers of the conflict are celebrating - even though it appears increasingly likely that Abubakar Shekau, the Islamist extremist movement's notoriously violent leader, is dead, its strongholds overrun and remaining fighters scattered.