They killed everyone they could find in the remote village of Cinq. They murdered with guns and machetes and set babies and pregnant women on fire. They attacked the clinic and killed 90 patients and medical staff.

The April 24 attack was carried out by one of Africa’s newest armed militias: Bana Mura.

The group has destroyed at least 20 villages in the Kasai region of the Democratic Republic of Congo over the last two months, according to the United Nations .

In a statement Tuesday, the U.N. commissioner for Human Rights, Zeid Raad Hussein, called the region a “landscape of horror.”

Here is what you need to know about the new crisis threatening to plunge the country into a new civil war:

Who are the Bana Mura?

Last year, an anti-government rebel group named Kamuina Nsapu sprang up in the opposition-dominated Kasai region. As the insurrection spread, human rights groups accused both the rebels and the Congolese army of committing atrocities.

In recent months, a new militia appeared, calling itself the Bana Mura. Filled with ethnic rivals of the Kamuina Nsapu, the militia appears to have been created, armed and supported by the government, according to Hussein, the U.N. human rights commissioner.

In the last two months, the Bana Mura carried out horrific attacks on villages aligned with the rebels, he said.

“My team saw children as young as 2 whose limbs had been chopped off. Many babies had machete wounds and severe burns,” Hussein said.

“One 2-month-old baby seen by my team had been hit by two bullets four hours after birth. The mother was also wounded. At least two pregnant women were sliced open and their fetuses mutilated.”

He said witnesses testified that members of the Congolese armed forces and police accompanied Bana Mura during its attacks while government agents or officials had armed and directed the group.

42 mass graves were found and two U.N. investigators, including an American, were killed. Will the deaths be investigated?

The U.N., Human Rights Watch and other groups have called for an independent international inquiry into the massacres, and the U.N. Human Rights Council last week authorized such a probe.

But the Congolese government has rejected that idea as a threat to its sovereignty, and without its cooperation any investigation is unlikely to get far.

Human rights advocates want to examine the mass killings as well as the slayings of U.N. investigators Michael Sharp of the U.S. and Zaida Catalan of Sweden, who were kidnapped and killed in March with their Congolese interpreter, Betu Tshintela, and driver, Isaac Kabuayi.

The U.N. is conducting its own investigation into that incident. The Congolese government has released video to support its claim that the rebels were responsible, but there are doubts about its authenticity.

How many people have died in the fighting?

Because of the violence, it has been difficult to access parts of the Kasai region to assess casualties. The Catholic Church used reports from its parishes to produce the first comprehensive count: 3,383 dead since October.

In a dossier released Monday, the church said some of the attacks were carried out by government forces and some by militia groups. More than 3,800 houses have been destroyed, it said.

The death toll is sure to rise. Although the Kasai fighting has been going on since August, there has been no sign of peace negotiations to end the rapidly spreading conflict.

“There is no peace process,” said Stephanie Wolters, an analyst on the Democratic Republic of Congo with the Pretoria-based Institute for Security Studies in South Africa. “It will have to happen. But the government will not want to relinquish control over that process and that will delay and further escalate the situation.”

President Kabila's term expired in December but he still clings to power. What has been the impact?

One family has ruled the nation since 1997, when dictator Mobutu Sese Seko was toppled by Laurent Kabila. He was assassinated in 2001 and succeeded by his son, Joseph Kabila, who remains in office in violation of term limits set out in the constitution.

The family’s vast business interests help explain why the family is reluctant to give up power, Wolters said.

The government delayed elections last year, saying that 18 months were needed for the voter-registration process. It now promises election by the end of 2017, though it has made little progress toward that goal.

Late last year, when the opposition held protests in the capital, Kinshasa, over Kabila's refusal to leave office, security forces responded with violence, leaving dozens dead.

Meanwhile, efforts to negotiate a transitional government have had little success, and Kabila has appointed his own prime minister and government.

Kabila has always struggled to control the country, with its sprawling geography, terrible roads and myriad armed groups, but his lack of legitimacy has further weakened his control, according to Wolters.

“The impression about Kinshasa is that it is clinging to power and is willing to take the country with it,” she said.

As Kabila’s legitimacy has waned, signs of chaos have spread across the country. Last month, some 4,200 prisoners, including high security offenders, broke out of prison in Kinshasa.

“The disproportionate response of the army in Kasai, the disproportionate response in Kinshasa to the opposition protests, these are all signs of a regime that knows it doesn’t have many choices left,” Wolters said. “It’s all signs of end-of-regime desperation.”

What do the Congolese people want?

Congolese citizens want elections as soon as possible and for Kabila to leave power, according to a nationwide opinion poll conducted in May by the Congo Research Group at New York University.

It found that 24% of people approve of Kabila and that 83% support a deal made between the government and opposition parties in December to hold elections by the end of the year.

Kabila has lagged behind prominent opposition figures in other polls by the group.

The death of Etienne Tshisekedi, a veteran leader of the main opposition party, the Union for Democracy and Social Progress, in Brussels in February has divided and weakened the opposition and fueled uncertainty over whether Kabila will leave office peacefully. The government has not allowed his body to be repatriated, perhaps out of fear that the return would spark new opposition protests.

“People continue to protest against Kabila. That’s not going away,” Wolters said. “It’s very clear that the government lacks legitimacy. There’s still no electoral calendar. There’s still no language about Kabila leaving office.”

robyn.dixon@latimes.com

Twitter: @RobynDixon_LAT