In Nigeria, Boko Haram-style violence radiates southwards

As long as violence perpetrated by Islamist militants was more or less contained in Nigeria's remote northeast, the attitude of many citizens and expatriates in the more prosperous south was a shrug of the shoulders.

But growing evidence that Boko Haram, or other violent groups or individuals inspired by it, are radiating attacks from their northeastern heartlands across Africa's most populous country has many Nigerians feeling that nowhere is safe.