At least 15 village traders were shot dead in northern Nigeria's Zamfara state as they returned from a market on Thursday night.
The local police commissioner told AFP that armed robbers waylaid the traders, who were travelling in an open truck, and opened fire. They burnt some of the bodies in the truck.
The agency reports that villagers said 100 people came out of the bush and stopped the truck.
The attackers' motive may be robbery.
The incident reportedly occurred close to the town of Birnin Magaji, several hundred kilometres west of Kano, where nearly 200 people were killed in a wave of gun and bomb attacks last week.
The BBC's Haruna Shehu Tangaza in the neighbouring state of Sokoto says the trouble may be linked to several incidents in the village of Lingyado in Zamfara state.
Earlier last year, vigilantes from Lingyado evicted a group of people from the village who they suspected of being behind a series of cattle and other robberies.
Those flushed out regrouped and attacked the village with heavy weaponry - including rocket-propelled grenades - a few months later, killing 26 villagers.
Some believe the attack on Thursday night has the hallmarks of the group as the traders from Birnin Magaji village were ambushed and set alight, our reporter says.