Q+A-Unrest in Nigeria's oil heartland

May 15 (Reuters) – Nigeria’s main militant group has declared an “all-out war” in the creeks of the Niger Delta after a military offensive against one of its major camps in the heart of Africa’s biggest oil and gas industry.

Below are some questions and answers about how serious the escalation of violence is and what the implications might be.

Why is the delta important?

Who are the militants?

How serious are the threats?

What impact for the Nigerian economy?

Why is the region so hard to secure?

Reuters