The UN food agency on Tuesday voiced concern for the 125,000 Nigerian refugees who have fled to southeast Niger, where Boko Haram militants have launched attacks in recent days.
"The World Food Programme is particularly concerned by the attacks in the north of Nigeria which are spreading to Niger, forcing thousands of people to flee," WFP spokeswoman Elisabeth Byrs said.
Byrs stressed "the appalling situation" in which refugees live in the Diffa region, where the population has almost doubled and food stocks are becoming scarce.
Nigeria's Islamist Boko Haram group has since Friday launched three large-scale attacks in the Diffa region, which borders the northeastern Nigerian state of Borno where the militants control large swathes of territory.