Nigerian farm massacre: What we know

Nigeria has been stunned by the slaughter of scores of people on the weekend in the country's jihadist-ravaged northeast.

Armed assailants on motorbikes attacked villages outside the city of Maiduguri, the capital of Borno state, leaving at least 76 dead, according to the authorities.

The massacre set a new benchmark of brutality -- in one case, the attackers tied up farm labourers working on rice fields before slitting their throats.

Here is what we know so far:

What happened?

Around 40 attackers armed with machetes and guns surrounded some 60 farm workers outside an abandoned house in the village of Koshobe on Saturday afternoon, according to the testimonies of two survivors obtained by AFP.

The elderly were set aside while 43 younger workers were slaughtered.

The assailants then headed for the rice fields, where they "engaged in murderous insanity, grabbing workers, tying them up and slitting their throats," said one the survivors, a 24-year-old.

The authorities said Tuesday that the death toll had increased from 70 to 76, but warned it could rise further as local teams search the rice fields for more bodies.

Who carried out the attack?

Northeastern Nigeria has been in the grip of a jihadist insurgency that was launched by the Boko Haram group in 2009.

More than 36,000 people in Nigeria have died and around two million have fled their homes.

In 2016, Boko Haram split into groups -- one that remained loyal to historic leader Abubakar Shekau, while the other lined up with the Islamic State West Africa Province (ISWAP).

Both had been suspected of the attack, but the main group of Abubakar Shekau claimed responsibility in a video on Tuesday.

Yan St-Pierre of the Modern Security Consulting Group said the killing of civilians was "more akin to the operational methods of Boko Haram".

Vincent Foucher of France's CNRS research institute said that when Boko Haram began to "conquer cities in 2014-2015, the jihadists arrived in villages and executed all men old enough to pick up arms".

What was the motive?

The massacres coincided with the first local elections to be held in the area since 2009. The ballot has been repeatedly postponed due to the security crisis.

It also coincided with efforts by the authorities and aid agencies to help displaced people return to their homes and fields to avert a food shortage.

However, Boko Haram indicated it waged the assault as revenge for some villagers seizing its fighters and handing them over to the authorities.

"You thought you would apprehend our brethren and hand him over to the military and live in peace?" a Boko Haram jihadist said in the video.

What's the future for rural populations?

The 11-year conflict in northeastern Nigeria is in stasis, St-Pierre said.

The insurgents still hold swathes of land, and the boundaries under their control have not changed significantly.

The authorities retain control over the towns and use air power and artillery to harass the jihadists, but without making significant gains.

Pressure, meanwhile, is mounting to stave off an impending food shortage by returning displaced people to the land.

The UN says that on present trends, 5.1 million people will live in food insecurity by June 2021, a rise of a fifth in the space of a year.

Late last year, the Nigerian army decided to withdraw troops from advance positions after a spate of deadly attacks, and regrouped them in "super camps" that were claimed to be more effective and provide better protection.

But "the strategy means that there is a smaller military presence in rural areas," Foucher said. As a result, when a village comes under attack, it takes much longer for the army to intervene.

The plight of rural populations has been worsened by other factors, including poor harvests, coronavirus restrictions and the problems of humanitarian agencies operating in the area.

"They (the aid agencies) are increasingly targeted by terrorist organisations," St-Pierre said. Paradoxically, aid workers face suspicions within the army and among public opinion that they tacitly support the jihadists.