Nigeria's Islamist group Boko Haram on Wednesday claimed a set of fires at telecom masts across the north, while threatenning the staff of the Voice of America (VoA) radio network.

"We decided to launch attacks on masts of mobile telecom operators as a result of the assistance they offer security agents," said an email from the group's spokesman, also vowing "to not spare" any reporter from VoA, which last month reported that Boko Haram had entered talks with government.