Related Rule
Practice Relating to Rule 32. Humanitarian Relief Objects
According to the Report on the Practice of Nigeria, during the conflict in Biafra, the Nigerian Commissioner for Information maintained that “Nigeria would continue to stand by its promise to the ICRC to keep some ‘corridors of mercy’ safe from military activities so that relief supplies could at all times be channelled to Biafra through these corridors”. As no practice deviated from this, the report concludes that the opinio juris of Nigeria is that the protection of relief objects is part of customary international law. 
Report on the Practice of Nigeria, 1997, Chapter 4.2.