Officials in Nigeria say the militant group Boko Haram has freed about 190 people who were kidnapped in the northeastern state of Yobe in early January.
Authorities say the victims, most of them women, were released Friday and Saturday after being taken captive during a January 6 attack on the village of Katarko. During that raid, Boko Haram gunmen set much of the village on fire.
Officials say some people may still be held hostage.
Boko Haram has carried out mass abductions in the past. Last year, the group took nearly 300 schoolgirls from the town of Chibok.
In another development, suspected Boko Haram militants and Nigerian forces are battling Sunday in the the northeastern city of Maiduguri. There are no immediate reports of possible casualties.
Meanwhile, U.S. Secretary of State John Kerry will be in Nigeria on Sunday to meet with the country's two leading presidential candidates: incumbent President Goodluck Jonathan and main opposition candidate Muhammadu Buhari.
The State Department said Kerry would travel to Nigeria's largest city, Lagos, and emphasize the importance of ensuring that the presidential and parliamentary elections, set for February 14, are peaceful and credible.
Past elections in Nigeria have been marred by violence. Jonathan's disputed victory in the 2011 election triggered violence in the north that killed an estimated 800 people.
This year's elections are complicated by the rise of Boko Haram, which has killed thousands of people in the northeast and controls much of Borno state.