The schoolgirls, whose names and ages were not disclosed, were arrested last week. They were later released on bail, Tandahimba District Commissioner Sebastian Waryuba said late Monday.
He said people are looking to question two other girls in the district, which is on the Mozambique border.
Tanzania has one of the toughest laws against those who impregnate school-aged girls, sentencing them to at least 30 years prison. Officials said the penalties are intended to discourage early marriages and teenage pregnancies that lead to school dropouts.
But critics say that in its zeal to curb teenage pregnancies, the country is also hurting and shaming the vulnerable teenagers. Human rights groups have criticized authorities in the country for implementing policies that don’t allow schoolgirls to return to class after they’ve given birth.
Human Rights Watch said many girls regularly experience sexual harassment and exploitation by teachers in school and that schools lack adequate protection and confidential reporting mechanisms.