VERY misleading headline.
The Nigerian Army was fighting these guys.
That's an understatement. The (nominally Christian) Nigerian Army was chasing Muslim rebels in an area very much against the government. It's hard to believe any accounts from battles like this since either side could easily have started torching houses and both sides will blame the other.
AP quotes government officials as saying at least 185 dead. Things will get mighty dicey when more pipelines start getting blown up in Africa's largest oil producer. Remember what we did to keep the oil flowing from Libya.