An empty space surrounded by fragile states,” is how one expert, David Okapi, describes Central African Republic (CAR).

Bordering South Sudan, the Democratic Republic of Congo and Chad, the sparsely-populated and extremely poor country has witnessed incessant conflict for more than three years. A coup by a mainly Muslim rebel coalition removed the then-president in 2013, sparking the formation of Christian militias motivated by vengeance.

But after broadly successful elections and a brief period of respite, fighting has increased again. More than 100 people have been killed in recent fighting—including six U.N. peacekeepers. And with U.S. and African forces withdrawing from CAR, fears that the fighting could spread are growing.

Where is Central African Republic?

A former French colony that is smaller than Texas, CAR occupies a landlocked position in the center of Africa, just below the volatile Sahel belt and above Congo, the site of Africa’s deadliest-ever civil war. Rich in diamonds and gold, CAR is ranked as the world’s third-most fragile state and shares borders with four others in the bottom 10, according to the Fragile States Index.

Who’s fighting who?

The conflict started when the Seleka —a coalition of mostly Muslim rebel groups from the northeast of the country— allegedly with the support of mercenaries from Chad and Sudan, overthrew Francois Bozize, a Christian who had been in power since 2003. The rebellion was a trigger for the rise of the anti-Balaka. These loosely organized Christian militias, who wear charms that they believe protect them from bullets, took control of the capital Bangui in 2013 and engaged in tit-for-tat killings of Muslims, following the Seleka’s targeted murders of Christians.

But, in recent fighting, the demarcation lines are less clear. The Seleka has disbanded, and its factions are fighting each other, says Lewis Mudge, a researcher at Human Rights Watch (HRW). One of these factions, the Renaissance of the Central African Republic, has actually recruited anti-Balaka elements into its coalition. “That was the first time we’d ever seen Seleka with anti-Balaka working together,” says Mudge.

Is it a religious war?

Religion has clearly played a role in the conflict, but the makeup of the opposing sides is also a reflection of the landlocked country’s demographics, says David Smith, the director of Okapi Consulting, who was previously part of a now defunct U.N. mission there between 1998 and 2000. Only around 8.5 percent of CAR’s population is Muslim—compared to 89.5 percent Christian—with the majority living in the northeast, says Smith. The Seleka formed as a result of grievances against former President Bozize’s scorched earth policy in the region: destroying crops or other resources that could be used by an invading army.

Read more: Why the U.S. and Uganda are dropping the hunt for warlord Joseph Kony

HRW researcher Mudge also points out that the war is not a religious conflict in the sense of one side trying to impose its belief system on another. The Seleka cannot be defined as Islamist in the sense of wanting to convert CAR into a Muslim state. “They never tried to force people to convert, they never banned alcohol. On the contrary, most Seleka fighters that I knew consumed copious amounts of alcohol,” says Mudge.

Who’s keeping the peace?

In the absence of an effective national army—and following the end of a 2,000-strong, three-year French military mission in CAR in 2016—the burden of conflict prevention has fallen on the 13,000 U.N. peacekeepers stationed in the country since 2014. The mission has helped defuse the violence and, most notably, marshaled a largely-peaceful general election held in CAR early last year, which saw former prime minister and ex-math professor Faustin Archange Touadera elected.

But allegations of sexual exploitation and abuse have blighted the mission. Over the past three years, 80 allegations have been made against U.N. peacekeepers in CAR, 10 of which have been substantiated. The mission has also suffered from a lack of resources and under-financing, says Smith. “It’s the poor cousin of most peacekeeping missions,” he says.

How will it end?

The recent uptick in fighting has observers worried. Recent attacks in the town of Bangassou have resulted in some 3,000 people fleeing across the border into Congo. The Red Cross said Wednesday that it had found 115 bodies and the U.N.’s human rights chief, Zeid Ra’ad Al Hussein, said the spread of conflict into previously peaceful areas like Bangassou “should set off loud alarm bells.”

More violence is inevitable, according to Mudge, since American and Ugandan forces previously stationed in Obo in the far southeast—where they were engaged in an ultimately unsuccessful hunt for Ugandan warlord Joseph Kony — announced they would be pulling out of CAR, leaving a power vacuum. “[The withdrawal] couldn’t happen at a worse time.… It’s safe to assume that this violence is going to keep spreading,” Mudge said.