Who are Boko Haram?
Boko Haram opposes any political or social activity that may be viewed as Western. This is why women or girls in the process of being educated are sometimes a target.
The Islamist group or sect, Boko Haram, was founded by Mohammed Yusuf in 2002 but he was killed by authorities in 2009. The group reformed and in the last few years have escalated violence once again.
Christian places of worship have been targeted but in late 2011 a mosque was also attacked. At that time we wrote "On Christmas day 2011 bomb attacks in Nigeria killed Roman Catholics as they attended churches around the country. At least 42 people were killed and around 90,000 have been displaced.
Even before this week's attacks Amnesty International put the death toll so far this year as 1,500. According to Amnesty terrorist action and reprisals by Nigerian forces have both contributed to an increase in killings. They claim that the Nigerian army killed 600 people following a suspected Boko Haram attack last month reports BBC News.