Chad has withdrawn hundreds of troops from neighbouring Niger, where they were helping local forces fight Boko Haram Islamist militants, humanitarian sources and officials said.
The pull-out over the past two weeks could weaken a region-wide struggle against militants who have killed tens of thousands of people, forced many more to flee and triggered a humanitarian crisis.
There was no immediate explanation or comment from defence officials in Chad.
The move came a month after the vast central African country complained about an unexpected US travel ban imposed on its nationals. Chad warned at the time the order could affect its security commitments – which include its involvement in the US-backed fight against Boko Haram.
Residents said the withdrawal had impacted on Niger’s Diffa region, with a string of attacks by Boko Haram militants crossing over from Nigeria.
Ibrahim Arimi from the border village Bosso said banditry had increased since the Chadian troops started leaving and he had been temporarily moved to another village for safety.
Diffa parliamentarian Lamido Moumouni said residents started complaining. “They have come to rely on the forces so there is a perception security will be lacking,” he said.
At its peak in 2016 after an attack in Bosso, Chad had 2,000 troops in Niger to help counter Boko Haram although security sources said this has since fallen.
Boko Haram attacks Chad, Niger and Cameroon from its base in north-east Nigeria. Its eight-year bid to carve out an Islamist caliphate has driven millions from their homes – more than 200,000 of them are now based in Diffa, with little prospect of returning home.
Thousands camp alongside an unfinished highway in the middle of a barren savannah with few resources.
Chad soldiers also occupy front-line positions in a peacekeeping force in northern Mali