Residents of a Nigerian village on the shore of Lake Chad say at least 50 residents are missing after a raid by suspected Boko Haram militants.
A witness told the BBC that 26 people were also killed during the raid on the village of Doron Baga on Sunday.
The remote region has poor communication links, meaning news of the raid took days to emerge.
Nigeria has been plagued by attacks by the Boko Haram Islamist group in recent years, particularly in the north-east.
In April, Boko Haram caused global outrage by abducting more than 200 girls from their boarding school in the remote down of Chibok in Borno state.
It is unclear exactly how many people were seized during the attack.
Some of the villagers tried to fight the attackers off, but they were unable to stop the raid, a villager elder told the BBC’s Hausa service.
The militants then burnt down some houses and rounded up a group of 50 people, he said.
They were mainly women but also included some boys and girls, he added.
Other survivors say young men were also taken possibly to be turned into Boko Haram fighters.
Witnesses from the village told reporters about the attack after reaching the state capital of Maiduguri.
The Nigerian military has not commented on the attack.
Who are Boko Haram?
- Founded in 2002
- Initially focused on opposing Western education – Boko Haram means “Western education is forbidden” in the Hausa language
- Launched military operations in 2009 to create an Islamic state
- Thousands killed, mostly in north-eastern Nigeria – but also attacks on police and UN headquarters in capital, Abuja
- Some three million people affected
- Declared terrorist group by US in 2013
Who are Boko Haram?
Profile: Boko Haram leader Abubakar Shekau
A state of emergency was declared in Borno and two other north-eastern sates last year to help the military crush the insurgency but the militants have stepped up attacks since then.
The schoolgirls abducted in April are thought to be held in the vast Sambisa forest, along Nigeria’s border with Cameroon.
The group has also carried out a wave of bombings and assassinations, including that of moderate Muslim leaders opposed to its ideology.