African Union Convention for the Protection and Assistance of Internally Displaced Persons in Africa (Kampala Convention), Article 9(2(b))
State parties shall provide internally displaced persons to the fullest extent practicable and with the least possible delay, with adequate humanitarian assistance, which shall include food, water, shelter, medical care and other health services, sanitation, education, and any other necessary social services, and where appropriate, extend such assistance to local and host communities.

UN Guiding Principles on Internal Displacement, Principle 3(2)
Internally displaced persons have the right to request and to receive protection and humanitarian assistance from national authorities. They shall not be persecuted or punished for making such a request.