Police said 39 people were seized on Sunday when they went to a meeting in the forest near Magamin Diddi village in the Maradun municipality of northwest Zamfara State.
Some local residents and officials said the number could be as high as 50.
According to a Zamfara State Police Command statement, the victims were meeting relatives of a bandit leader in an attempt to broker peace and ease restrictions on movement imposed on the community.
Zamfara is at the centre of a long-running security crisis in which armed groups, locally referred to as bandits, carry out mass kidnappings, killings and village raids. The violence has disrupted farming and displaced thousands.
Security forces have deployed personnel and intelligence assets to locate the victims, the police statement added.
Several individuals were reported by locals to have been released to convey the kidnappers' ransom demands back to the village.
Bashar Aliyu, a resident of Magamin Diddi, said the armed group was demanding 125 million naira ($A130,375) for the release of those abducted.
In many communities, residents have resorted to negotiating directly with armed groups to gain access to farmland or secure the release of abductees, a practice authorities have discouraged but struggled to prevent.
Nigeria is facing a complex security crisis, especially in the north, where a more than decade-long insurgency and the activities of armed groups that carry out kidnappings for ransom and illegal mining have heightened the country's security challenges.
The insurgency in Nigeria's northeast has killed thousands of people and displaced millions, according to the United Nations.
with AP
