More than 677 females were declared rescued last week.
The army has deployed ground troops into Sambisa Forest after weeks of punishing air raids on the area.
“The assault on the forest is continuing from various fronts and efforts are concentrated on rescuing hostages of civilians and destroying all terrorist camps and facilities in the forest,” said defence ministry spokesman Major-General Chris Olukolade.
Sambisa Forest is the last hold-out of the Islamic militants. President Goodluck Jonathan, whose term ends this month, pledged on Thursday to “hand over a Nigeria completely free of terrorist strongholds”.
It is not known how many girls, women, boys and men Boko Haram has kidnapped during its nearly six-year-old rebellion. The Nigerian army has reported rescuing only females.
It was reported that some women shot at their rescuers and were killed, with Boko Haram using them as an armed human shield for its main fighting force.
Most of the females are traumatised, said army spokesman Colonel Sani Usman. Nigeria’s military says it has flown in medical and intelligence teams to screen the rescued girls and women and find out their identities.
It is still not known if any are the schoolgirls kidnapped from a boarding school in Chibok town a year ago – a mass kidnapping that outraged much of the world.
A counsellor who has helped rehabilitate other women held captive by Boko Haram said that some now identify with the insurgents’ extremist ideology after months of captivity and forced marriages.
It remains unclear if some of the women had willingly joined Boko Haram, or are family members of the fighters.
Boko Haram began kidnapping civilians after Nigeria’s military detained the wives and children of several militant leaders. They were freed amid failed peace negotiations in 2013.
Some of the freed women and girls are pregnant, Muhammad Gavi, a spokesman for a self-defence group that fights Boko Haram, said citing information from group members who have seen the females.