Survivors say militants screaming "God is great!" killed at least 21 civilians and set homes ablaze as they rampaged through a village in northeastern Nigeria, an area that has been attacked several times.

Villagers who trekked nearly 100 kilometers (60 miles) to Maiduguri, capital of Borno state, said 30 Islamic extremists bearing guns and explosives rode into Sandiya village on Thursday in all-terrain vehicles and on motorbikes. The news came when survivors arrived Saturday since cell phone service has been cut by the military.

Reports of similar attacks in neighboring Yobe state could not be confirmed immediately. The area was tense Sunday with increased military checkpoints and patrols.

Northeastern Nigeria is under a state of emergency as the army battles an Islamic uprising that has killed thousands in four years.