Incursions by Islamist militants into western Niger from neighbouring Mali have caused more than 16,000 people to flee their homes since the start of the year, the UN said Wednesday.
"Growing insecurity since January has caused the number of displaced people to leap," the UN's Office for the Coordination of Humanitarian Affairs (OCHA) said.
"More than 16,000 people are internally displaced in the regions of Tillaberi and Tahoua," it said, referring to two regions near the border with Mali.
It blamed "repeated attacks by armed non-state groups" and an "intensification of inter-community conflicts" on the Niger-Mali border.
In May alone, 2,867 people were added to the list of known displaced, compared to 540 in January.
Niger is one of a number of poor, fragile countries in the Sahel that have been hit by a jihadist revolt.
The country is part of the so-called G5 Sahel group, which aims at creating a 5,000-member joint force to tackle the insurgents and criminal gangs which roam the remote region.