At least 110 civilians were killed and many others wounded in an attack on farmers in the north-east Nigeria, according to the UN.
Earlier reports said more than 40 farmers were killed during the attack at a rice farm near Maiduguri.
This latest information indicates that the number of casualties is far higher than the figure given by the Nigerian authorities.
The UN said its resident humanitarian coordinator in Nigeria, Edward Kallon, armed mean on motorcycles led a brutal attack on farmers harvesting rice in Koshobe, in Borno state. Kallon condemned the attack and called for the perpetrators to be brought to justice.
Earlier on Sunday, the governor of Borno asked for more young people to be recruited as vigilantes to help fight the insurgency in the region. He made the call after witnessing the burial of 43 people killed in the attack.
Reports say the assailants tied up the agricultural workers and slit their throats. He told media that residents of the state faced a dilemma – either risking being killed on their farms or dying of hunger while staying at home for fear of attacks.
No group has claimed responsibility for the killings. The Islamist groups, Boko Haram and the Islamic State West Africa are both active in the region.