The release of the girls may give a boost to Buhari who has hardly appeared in public since returning from Britain in March for treatment of an unspecified illness. He made crushing the insurgency a pillar of his election campaign in 2015. The army has retaken most of the territory initially lost to the militants but attacks and suicide bombings by the group have made it nearly impossible for displaced persons to return to their recaptured hometowns. "The President directed the security agencies to continue in earnest until all the Chibok girls have been released and reunited with their families," the presidency said. INSECURITY More than 20 girls were released last October in a deal brokered by the International Committee of the Red Cross. Others have escaped or been rescued, but 195 were believed to be still in captivity. Buhari said last month that the government was in talks to secure the release of the remaining captives. Although the Chibok girls are the most high-profile case, Boko Haram has kidnapped thousands of adults and children, many of whose cases have been neglected. Although the army has retaken much of the territory initially lost to Boko Haram, large parts of the northeast, particularly in Borno state, remain under threat from the militants. Suicide bombings and gun attacks have increased in the region since the end of the rainy season late last year. Some 4.7 million people in northeast Nigeria depend on food aid, some of which is blocked by militant attacks, some held up by a lack of funding and some, diplomats say, stolen before it can reach those in need.