AFP/Niamey

Thirteen people were killed and three injured in an attack on a village in south-east Niger allegedly carried out by Boko Haram extremists, local officials said Wednesday.

"Thirteen people were executed and three others suffered gunshot wounds in an attack by Boko Haram Tuesday evening in Ala village," Malam Ligari, a local official in the Diffa region, which has been repeatedly attacked by the jihadists, told AFP.

"This was a fast operation," conducted between "8:00 and 10:00 pm (19:00 and 21:00 GMT)," Ligari said, adding that the assailants came on foot after crossing the Yobe river --  which forms a natural border between Niger and Nigeria in the area -- by canoe.

"Boko Haram militants came in number. They burned cars, houses, stores," the private radio station Anfani reported.

Since February, the Diffa region has suffered several attacks blamed on the Nigeria-based Islamist radicals, including one in June in which 38 people were killed, including 10 children.

On Tuesday, Niger's parliament voted to extend for another three months the state of emergency declared in February in the region.

"The biggest problem we have is controlling the border with Nigeria," Niger's Interior Minister Hassoumi Massaoudou told deputies.

Cameroon, Chad and Niger have formed a military alliance with Nigeria and Benin to battle the extremists, who this year declared allegiance to the Islamic State.

The Islamists' grip on the region has suffered as a result of offensives launched by local armies. 

But the group maintains strongholds in remote parts of north-east Nigeria, the Mandara mountains on the Nigeria-Cameroon border and the islands of Lake Chad.