An official of the National Emergency Management Agency said the attackers hit Dumba village in Borno state before dawn on Tuesday and slit their victims' throats - a new strategy since gunfire attracts security forces.
He said the attackers gouged out the eyes of some victims who survived.
Dumba is near the fishing village of Baga where security forces in March gunned down 187 civilians in retaliation for an attack by extremists.
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