Beheadings, mass graves, kidnapped foreigners, child soldiers: a tribal insurrection in the Democratic Republic of Congo's Kasai region has killed hundreds of people and risks further destabilising the fragile central government.
Congolese officials face growing international pressure to curb the violence, while the UN Security Council prepares to vote Friday to cut down its peacekeeping mission in the vast central African country.
Here is what we know about the uprising:
What sparked the rebellion?
Fighting in the central region of Kasai erupted in August 2016 when DR Congo forces killed tribal chief Jean Pierre Mpandi, also known as Kamwina Nsapu, who had rebelled against the government of President Joseph Kabila.
Mpandi was designated to succeed his uncle as head of the Bajila Kasanja clan of the Lulua tribe in 2011 after his return from exile following a conviction in a diamond trafficking case.
The chieftain, whose tribal name refers to a poisonous black ant, had practised as a doctor after claiming he studied in China and India even though he never finished secondary school.
Tensions flared after officials considered to be close to Kinshasa were appointed to powerful posts at the expense of tribal chiefs, angering the local community.
Resentment of Kabila's administration runs deep in the region, which had overwhelmingly supported opposition leader Etienne Tshisekedi in the 2011 presidential election.
Before he was killed, Mpandi had called on his militia to fight anyone representing the government, posting an audio appeal online for the "liberation of Congo".
By January, Kasai-Central provincial governor Alex Kande said Mpandi's movement had "morphed in total anarchy into a deadly guerrilla force".
The violence has spilled over into neighbouring provinces, leaving at least 400 people dead.
The region is rich in diamonds but the industry has collapsed and much of the population lives without basic needs like water and electricity.
Kabila has drawn criticism for being slow to enact power-sharing measures with opposition leaders, part of a deal that allows him to stay in power until elections at the end of 2017, a year after the end of his mandate.
Who are the militias?
Mpandi's fighters include men, women and even children from remote areas of Kasai, home to the country's third and fourth largest cities.
Initiation rites include jumping through flames after drinking a locally-produced alcohol believed to have powers to make people invincible.
Armed with rudimentary weapons such as slingshots, machetes, sticks, arrows, brooms and voodoo charms, according to UN sources, the fighters wear red bandanas on their heads or arms.
Their tactics include burning government property, torturing and beheading police or intelligence agents, government sources say.
The bodies of two UN researchers were found this week after being kidnapped in Kasai, drawing further attention to the region's violence.
What is the international community doing?
The UN, EU and African Union on Tuesday expressed "grave concern" about the violence while also urging government forces to "exercise restraint in the efforts to restore order in the Kasai".
UN Secretary-General Antonio Guterres has asked the Security Council to boost its forces in DR Congo, the UN's largest and costliest peacekeeping mission which is known as MONUSCO.
But the council is expected to vote Friday to reduce its presence there and the US, which wants to scale back on UN spending, has called for a review of the mission.
The force's authorised strength of over 19,800 will be cut by 3,600, according to US ambassador Nikki Haley, although 3,100 of these places are already unfilled.
In February, MONUSCO accused the Kamwina Nsapu militia of "atrocities... including the recruiting and use of child soldiers," while also condemning the response of DR Congo forces for "a disproportionate use of force".
On Monday, the government claimed militiamen killed 39 policemen last week in an ambush but provided no evidence, saying the corpses had been buried in a mass grave by Nsapu followers.