What gave rise to the attack in a mosque in Edo state according to the news?

Thousands of Muslims living in southern Nigeria are reported to be fleeing north following growing tensions after recent sectarian attacks. Many Christians are reported to be heading in the opposite direction. Last week, dozens of Christians were killed by the militant Islamist Boko Haram as gunmen from the group shot at random in churches, at a community centre and a beauty salon. On Monday, a mosque was reportedly attacked in Edo state in the south, injuring 10 people—apparently in response to last week’s fatal shootings of Christians. The president of the Nigerian Christian Association, speaking before the mosque attack, expressed his fears that Nigeria may be on the brink of a civil war.