Niger’s army killed at least 30 suspected Boko Haram fighters in villages just over the border with Nigeria.

The army launched the operation on Thursday, a day after Book Haram gunmen killed at least a dozen villagers on the Niger side of the border.

Boko Haram has started calling itself the Islamic State’s “West Africa Province” since pledging allegiance to the hardline militant group which controls large areas of Syria and Iraq.

At least 30 gunmen were killed when the Niger’s army attacked.