Anthony Iwuoma
Mamu said those released are Oluwa Toyin-Ojo; Hassan Lawan; and Ayodeji Oyewumi, adding that Gladys Brumen, was released last week.
Meanwhile, 39 victims are still in captivity of their abductors.
Kidnap for ransom by terrorists has become rampant in Nigeria, which is reeling under crushing insecurity especially in the North-east and North-east of the country.