"Troops have this afternoon captured & destroyed three camps of terrorists inside the Sambisa forest & rescued 200 girls & 93 women," defence spokesperson Chris Olukolade said in a text message, referring to the area in northeast Borno state where the Islamists have bases.
"It is not yet confirmed if the girls are the Chibok girls. The freed persons are now being screened & profiled," he added.
Olukolade gave no indication as to how long it would take for the hostages to be identified.
Boko Haram claimed the abduction of 276 girls from a secondary school in Chibok, also in Borno, on April 14 of last year.
Fifty-seven girls escaped within hours of the attack but 219 remained in captivity.
In the weeks following the mass abduction, Nigerian security sources and locals in Borno said there were indications the girls had been taken to the Sambisa Forest.
But defence officials and experts agreed that they were likely separated over the last 13 months, casting significant doubt on the possibility that they were being held together as a group.
Boko Haram's leader, Abubakar Shekau, has vowed to "marry them off" or sell them as "slaves."
Boko Haram has also been blamed for hundreds of other kidnappings, especially targeting women and girls across northeast Nigeria.
Amnesty International estimates that the Islamists have kidnapped at least 2,000 women and girls since the beginning of last year.
The Chibok attack brought unprecedented worldwide attention to Nigeria's Islamist uprising.
It also sparked sharp criticism of the government's initial response to the drama, with outgoing President Goodluck Jonathan accused of indifference and of trying to downplay the size of the kidnapping.
Celebrities and prominent personalities including US First Lady Michelle Obama joined the Twitter campaign #BringBackOurGirls that attracted supporters worldwide.
Earlier this month, countries around the globe took part in marches and candlelight vigils to mark the first anniversary of the kidnappings.
Read: World must do more to free Nigerian schoolgirl hostages, says Malala
Nobel laureate Malala Yousafzai, who was shot and nearly killed by the Taliban for advocating girls' education, used the occasion to renew calls for their release, describing the girls as "my brave sisters".
The 17-year-old criticised Nigerian and world leaders for not doing enough to free the girls.
Twenty-one of the 57 girls who escaped are currently studying at the American University of Nigeria in Yola, the capital of neighbouring Adamawa state.
Boko Haram, whose name translates roughly from the Hausa language as "Western education is sin", is seeking to create a hardline Islamic state and has pledged allegiance to the Islamic State jihadist group.
Boko Haram's six-year insurgency in northeast Nigeria has left at least 15,000 dead and some 1.5 million people homeless.
The Nigerian military has in recent months claimed a string of successes against Boko Haram after launching a joint offensive against the militants with the help of soldiers from Chad, Cameroon and Niger.
But Boko Haram has been fighting back, and Nigerian troops were notably forced to retreat from the group's Sambisa Forest stronghold this week after a landmine blast killed one soldier and three vigilantes.
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