Motorcycle-riding armed bandits operating out of abandoned forest reserves are ransacking communities in Nigeria's north-west.

The groups are the latest to join Nigeria's lucrative kidnap for ransom industry, and are quite brazen in their operations.

In the last decade more than 8,000 people have been killed in the states of Kebbi, Sokoto, Niger and Zamfara, according to the International Crisis Group.

But recent attacks in the president's home state of Katsina, where more than 100 people were killed in attacks between April and June, have led to protests and calls for his resignation.

On two separate occasions the bandits targeted villagers who had received food handouts from the government during the coronavirus lockdown.

"They were about 200 on motorbikes, each bike rider carried a passenger and they all carried AK47 guns," Bashir Kadisau, an eyewitness, told the BBC.

He said he climbed to the top of a tree when he saw the large number of motorcycle riders coming into Kadisau village, and saw the attackers loot shops, steal cattle and grain, and shoot people who were fleeing.

Climate change fuels conflict

The attacks are rooted in decades-long competition over resources between ethnic Fulani herders and farming communities.

The herders are mostly nomadic and can be found on major highways and streets across the country herding their cattle, but they have become involved in deadly clashes with farmers in Nigeria's north-western and central states.

This is because these areas have suffered massive deforestation, due to the impact of the Sahara Desert spreading south, causing arable farming land to disappear and water to become scarce.

"The persistent clashes led to the formation of armed self-help groups, called vigilantes, by both sides for protection," security analyst Kabiru Adamu told the BBC.

'Kidnapping more lucrative than herding cows'

Armed groups within Fulani communities are being accused of resorting to criminality.

"The herders now see kidnapping and pillaging as more lucrative than the herding.

"The biggest cow would go for 200,000 naira but one kidnapping would fetch millions," Dr Adamu said.

Nigeria's Fulani herders deny the accusation.

The main Fulani cattle-breeders association, Miyetti Allah (Hausa for Thank You God), said they are the ones mostly affected by the activities of the bandits and that hundreds of their members have been kidnapped.

"Our cows have been rustled. The bandits are a bunch of criminals comprising all sorts of groups. We have lost 30% of cattle in Nigeria to different types of crises," Miyetti Allah's national secretary Baba Othman Ngelzarma told the BBC.

He said the attackers in Nigeria's north-west were "foreign herders from neighbouring countries".