A man calmly sets fire to a house, watched by a group of at least 12 men dressed in fatigues, helmets, and black webbing consistent with those worn by an elite army unit in Cameroon.

"I want to die," a village chief tells his tormentors as they beat and threaten to kill him. They appear to be members of a separatist militia.

Captured on video and shared widely on social media, these are among dozens of clips that have been pouring out of Cameroon over the last six months, some of which have been analysed by BBC Africa Eye.

Some of them show burning villages. Others record acts of torture and killing. Many are too graphic to show.

Though often confusing and hard to verify, these films show a nation sliding towards a brutal civil war as the government tries to suppress an armed insurgency in the English-speaking areas of western Cameroon.

The crisis in Anglophone Cameroon:

Began in 2016 with demonstrations by English-speaking lawyers, students and teachers
Protests against marginalisation by the French-speaking majority met with a crackdown
Activists arrested, and several protesters shot by security forces
Separatist demands for an independent state grew, resulting in increasingly violence
Some symbolically proclaimed the independence of a new state called "Ambazonia"
Some 160,000 people have fled their homes in Cameroon, the UN says
More than 20,000 have fled to Nigeria
Journalists being denied access to conflict zones.

Colonial roots

This is a conflict that has been building for decades.

The division between Cameroon's French-speaking majority and its English-speaking minority has its roots in the colonial era.

Cameroon was colonised by Germany and then split into British and French areas after World War One.

After French-administered Cameroon gained independence in 1960, the two parts of the country formed a single nation the following year.

This followed a referendum when British-run Southern Cameroons voted to join the French-speaking Republic of Cameroon in 1961, while Northern Cameroons voted to join English-speaking Nigeria.

Even then, some English-speakers felt they had been forced into the new republic.

Cameroon became a federation of two states - one English-speaking, the other French-speaking - under one president.

A decade later in 1972, another public vote saw Cameroon dropping its federal form to become a unitary state.

Ever since, many Anglophones have complained that their regions were being neglected and excluded from power.

Schools torched by rebels

It is not just the government accused of committing abuses. Separatist rebels have also killed Cameroonian security forces and attacked civilians accused of working with the government.

The rebels have also attacked and burnt down schools - according to Amnesty at least 42 schools were attacked by armed separatists between February 2017 and May 2018.

Anglophone activists called for a complete school boycott last year to exert further pressure on the authorities. Amnesty has images of a teacher who was shot for keeping his school open.

A new video shows a village chief being beaten, apparently by a rebel who threatens to kill him.

The government says that 81 members of the security forces and more than 100 civilians have been killed by separatists in the past year.

No official figures are available for civilian and separatists' deaths at the hands of the security forces.

Prime Minister Philémon Yang has accused Cameroonians living overseas of using social media to "spread hate speech and terror" and "order murders".

This week, the gendarmerie - Cameroon's military police force - banned officers from using mobile phones or social networks such as WhatsApp, Facebook and Twitter without permission.

Aid agencies' efforts to assist civilians have been frustrated by the struggle to access conflict areas.

As Cameroon's Anglophone crisis continues, both the UK and France have discreetly pressed for dialogue.

The US Ambassador to Cameroon, Peter Barlerin, has taken a harder stance. He recently accused the army of burning and looting villages and also suggested that after 35 years in power, President Paul Biya might want to consider stepping down.

Cameroon faces increasing international scrutiny in its approach to the crisis, with general elections scheduled for October 2018.

Thousands of families have been forced from their homes by the fighting.

While 21,000 people have fled across the border into Nigeria, the UN estimates that a further 160,000 are displaced within Cameroon.

Many others are still hiding in the forest. (BBC)

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