Nigeria violence: Boko Haram blamed for new massacre

There are reports of continuing atrocities in Nigeria by the radical Islamist group Boko Haram, which kidnapped more than a 200 schoolgirls in April.

It is thought as many as 200 people have been killed in the last two weeks as a result of attacks in the Gwoza hills, near the border with Cameroon.

Will Ross reports on what he describes as "a brutal campaign of violence".