UNHCR, the UN Refugee Agency, is deeply saddened by the reports of the deaths of at least 20 people, among them women and infants, during a stampede for food and cash in Niger's Diffa region on Sunday.
The assistance was being distributed independently by visiting Nigerian authorities for Nigerian refugees hosted in the area.
Four refugees are among the dead while many others are injured. It is feared that the number of victims could rise as more information on casualties is received from hospitals and health centres in Diffa.
"We are shocked and saddened by these deaths," said UNHCR's Representative in Niger, Alessandra Morelli.
"We appreciate all efforts by individuals trying to help refugees but we strongly appeal for these efforts to be coordinated with local authorities in Niger as well as with humanitarian actors."
UNHCR, which was not involved in Sunday's distribution, has been providing protection services and assistance to refugees and those internally displaced in south-east Niger and has an aid distribution mechanism in place to ensure that this can be done in a safe and effective manner.
This region, bordering Nigeria's Borno State, currently hosts 263,000 people who have been displaced by violence in the Lake Chad Basin, of which almost half, some 120,000 are refugees. Refugees are overwhelmingly women and children from Nigeria, with a few thousand arriving recently from Chad.
UNHCR is providing emergency assistance to survivors in the form of medical care and psychosocial support and remains ready to support local authorities in their response to this tragedy.
In Niger and in the Lake Chad Basin, UNHCR leads the international response to protect those forced to flee their homes because of conflict and persecution. It has continuously been advocating for enhanced coordination between humanitarian and development actors in areas hosting forcibly displaced populations.