The Nigerian extremist group Boko Haram has crossed into neighbouring Niger and attacked two villages, killing 40 people.
Born in north-eastern Nigeria, Boko Haram last year began crossing the border attacking villages, mosques and churches in neighbouring countries - which finally prompted regional armies to band together against the radical Islamic group.
The fighters hit the villages of Lamana and Ngoumawa near the Nigerian border in the early hours of Thursday morning - looting stores and burning homes, said Yakouba Soumana Goah, the governor of the Diffa region where the attack occurred.
He added that the army went in pursuit of the attackers.
Boko Haram last attacked Niger in April and killed at least 58 people.
Boko Haram took control of a large swath of north east Nigeria until a multinational force this year forced them out of towns and villages but it still engages in cross-border hit and run attacks.
The six-year-old uprising is blamed for the deaths of some 13,000 people. More than 1.5 million have been driven from their homes, some across borders.