Boko Haram said it is building an Islamic state that will revive the glory days of northern Nigeria's medieval Muslim empires, but for those in its territory, life is a litany of killings, kidnappings, hunger and economic collapse.

The Islamist group's 5-year-old campaign has become one of the deadliest in the world, with around 10,000 people killed last year, according to the Council on Foreign Relations. Hundreds, mostly women and children, have been kidnapped.

It remains the biggest threat to the stability of Africa's biggest economy ahead of a vote on Feb 14 in which President Goodluck Jonathan will seek re-election.