The Nigerian military has lifted a ban on UNICEF operations in the ravaged northeast of the country. Earlier, the army had suspended the aid agency & accused it of training spies supporting Boko Haram jihadists. Boko Haram's Islamist insurgency has killed more than 27,000 people since it began in 2009 and has triggered a humanitarian crisis in the wider Lake Chad region, where the jihadists have stepped up attacks in recent months.