A Nigerian civilian defense officer says suspected Islamic extremist gunmen killed at least 20 people in an attack Monday on two villages on the outskirts of Chibok, the northeastern town where more than 200 schoolgirls were abducted in April.

Muhammed Abbas Gava, spokesman of a Nigerian civilian militia said that attackers struck Kamtahi and Galtimari villages Monday evening, burning houses and forcing residents to flee.

Borno State police command spokesman, Gideon Jubrin, said he was not aware of the incident.

This is the latest of a string of attacks in Borno state, including two suicide bombings on Tuesday at a crowded marketplace. Dr. Musa Taji, a medical doctor in Maiduguri, said at least 70 people were killed.