The group that claimed responsibility for the attack may have links to Boko Haram, a militant group known for its terror campaigns in the region.
A suicide bombing at a venerable newspaper suggests that journalists could now become routinely targeted by Boko Haram, says guest blogger G. Pascal Zachary.
But after a Boko Haram campaign that killed at least 1,000, and a government crackdown that killed the Islamist group's leader, there are questions as to what the two sides can discuss.
While the Nigerian military claims that the fighting with Boko Haram in the country's north is under control, the lack of information from the region fuels doubt about the military's success.
The Nigerian government's strategy for dealing with Boko Haram is based on its experience with militants in the Niger Delta, but Boko Haram's different grievances means those tactics may not work.