A Nigerian Islamist sect has claimed responsibility for the killing of a state television cameraman.

A spokesman for Boko Haram said in a statement Tuesday the group killed Zakariyya Isa because he was spying on them for Nigerian security services. The spokesman said information provided by Isa led to the arrest of many Boko Haram members.

Isa died Sunday in Maiduguri after being shot the night before, shortly after he left a mosque. There is no evidence he acted as an informant.

Last month Boko Haram threatened to attack journalists who “misrepresent” the group in their reports. The statement Tuesday said the sect will not hesitate to kill anyone who “steps on our toes.”

Boko Haram, which means “Western education is sinful” in the Hausa language, says it is fighting for an independent nation in western Nigeria that would be ruled by Islamic law.