Suspected Boko Haram militants have killed at least 14 people in an overnight attack on a village in south-eastern Niger.

"They executed at least 14 civilians," a security source said, referring to the village of Ala in the Diffa region near the Nigerian border.

A second security source saidthe assailants had looted the village and then set fire to the houses. Niger's army is pursuing the militants, he added.

Niger's Diffa region has suffered dozens of cross-border attacks this year by the Islamist militant group whose stronghold in northeast Nigeria lies just a few kilometres away.

Parliament on Tuesday approved a law prolonging a 15-day state of emergency for Diffa by three months in a bid to boost security.