Nigerian forces began attacking Islamist hideouts in the northeast on Thursday, May 16 security sources said, part of an offensive to wrest control of the region from increasingly bold and well-armed Boko Haram insurgents, according to Reuters.

Soldiers raided areas in the Sambisa Game Reserve, a remote savannah of some 500 sq km in Borno state where Islamists have established bases, two security sources who asked not to be named said. They did not give further details.

President Goodluck Jonathan this week declared a state of emergency in three northeastern states.