Concern over Boko Haram's 'Nigeria encroachment'

The Islamist militant group Boko Haram has released a video in which a fighter says he is part of a branch in Nigeria's western Niger state.

The group's more than decade-long insurgency has largely focused on the north-east of the country and the Lake Chad region.

A presence in Niger, Nigeria's largest state, would represent a worrying development, as it borders on the country’s capital, Abuja.

Analysts have voiced concerns that the dense mountainous and forest terrain in Niger state would be a natural haven for the militants.

Recent attacks by armed groups in the north-west of the country, including the president’s home state of Katsina, have led to protests in the region.

More than 100 people have been killed in attacks between April and June this year.

It is unclear whether these criminal groups have links with Boko Haram, although Ansaru, a Boko Haram splinter group affiliated with al-Qaeda, is known to be active in the region.