At least 110 rice farmers and fishermen have been killed in a village in north-east Nigeria in a suspected Boko Haram attack.
The attack took place in the village of Koshobe near the main city of Maiduguri, in the restive Borno region, on Saturday.
“At least 110 civilians were ruthlessly killed and many others were wounded in this attack,” said Edward Kallon, the UN resident co-ordinator in Nigeria.
“The incident is the most violent direct attack against innocent civilians this year.
“I call for the perpetrators of this heinous and senseless act to be brought to justice.”
Mr Kallon said there were reports that women might have been kidnapped and called for their immediate return to safety.
Workers in the village were tied up and had their throats slit in the horrific attack after armed bandits drove in on motorcycles.
“My thoughts are also with the rural communities in the area, who are shocked by the brutality of yesterday’s attack and fear for their safety,” Mr Kallon said.
“The entire UN system and the humanitarian community working to provide life-saving and development assistance to the most vulnerable in Borno State is outraged by the incident.”
Babagana Umara Zulum, the Borno state governor, attended a burial on Sunday in the nearby village of Zabarmari of 43 bodies recovered on Saturday.
“The entire country has been wounded by these senseless killings,” Nigerian President, Muhammadu Buhari said.
Mr Buhari said the government had supported the Nigerian army “to take all necessary steps to protect the Nigeria’s population and its territory”.
The attacks occurred as the long-delayed Borno state elections took place.
Frequent attacks by Boko Haram and rival group IS West Africa Province have delayed the voting.
Former Aviation Minister Femi Fani-Kayode on Sunday called out Boko Haram leader Abubakar Shekau over the killings.
Mr Fani-Kayode tweeted: “Boko Haram and its leader Abubakar Shekau are the greatest plague that has ever afflicted the Nigerian landscape.
"They must be crushed and wiped off the face of the earth.”
Extremists are increasingly attacking loggers, farmers and fishermen in Borno, accusing them of spying for the army and pro-government militias.
Last week, Boko Haram attacked Mr Zulum’s convoy, killing seven soldiers and two civilians.
He escaped unharmed but it was the third time he had been attacked by Boko Haram terrorists in the past three months.
In two attacks last month, Boko Haram killed 22 farmers working on irrigation fields near Maiduguri.
More than 30,000 people have been killed in the extremist insurgency in Nigeria, mainly in the north-east, and about 3 million people have been displaced from their homes since 2009, the UN Office for the Co-ordination of Humanitarian Affairs says.
The terrorism has spread to neighbouring countries Cameroon, Chad and Niger.