Fifty men with machine guns attacked a prison in the central Nigerian city of Bauchi on Tuesday, killing four people and freeing up to 800 prisoners before setting the prison on fire. The attackers are believed to be members of Boko Haram, the same extremist Islamic sect blamed for an anti-Christian uprising that ended with 800 dead in the northern city of Maiduguri last year. Many of the prisoners released were perpetrators of last year’s violence. Boko Haram translates to “western education is sinful” in the Hausa language. The group wants Muslim Sharia law imposed across all of Nigeria, a country that is more than 40 per cent Christian.