Maiduguri - A UN humanitarian official said on Saturday that relations with Nigeria remain "intact" following an unauthorised raid by Nigerian troops at a UN base in the country's conflict-torn northeast. Peter Lundberg told a press conference in Maiduguri that the United Nations was working with the Nigerian government to resolve the issue of Friday's search of the humanitarian camp known as the "Red Roof"."I am very pleased to report that our relationship of collaboration and trust are intact at this stage," the UN deputy humanitarian coordinator for Nigeria said."We are focused on the work ahead to ensure that the millions of vulnerable people in the northeast are supported with life-saving humanitarian aid," Lundberg added.The UN camp in Maiduguri is located at the epicentre of the conflict with Boko Haram jihadists who have been waging an insurgency since 2009.A UN source told AFP on Friday that the soldiers' search of the camp was illegal under international law and may have been triggered by inaccurate information that a Boko Haram leader, Abubakar Shekau, was at the facility.The Nigerian military, which claimed there was no sign it was a UN camp, issued a statement on Friday calling its "operation" a success but added that no suspect was found.General Ibrahim Attahiru, who commands operations in Borno state where Maiduguri is located, said on Saturday that the army "will continue to work toward providing and enabling a conductive environment to UN agencies to enhance their operations." "Peace building is a collective responsibility," he said in a statement.UN Secretary-General Antonio Guterres's spokesperson Stephane Dujarric said that the organisation had formally complained to the Nigerian government."There have been contacts - we understand from the government that this was a mistake. The raid should not have happened," he said at a daily briefing in New York on Friday.The raid happened against a backdrop of strained relations between the Nigerian military and foreign organisations seeking to relieve the humanitarian disaster engulfing the country's northeast.Over 20 000 people are estimated to have been killed over the eight years of the Boko Haram conflict and more than two million displaced. The UN estimates that nearly seven million Nigerians are in need of humanitarian aid.