Halima, a 25-year-old Muslim, could not hold back tears when we met again recently in Bossemptele, about 185 miles north of Bangui, in the Central African Republic. She was living under the protection of the Catholic Church, after the anti-balaka militia slaughtered more than 80 Muslims in Bossemptele.

For the past six months, such militias have sought to avenge the devastation wrought by the predominantly Muslim Seleka rebel group, which took power last March in this majority-Christian country.

When we first spoke, two days earlier, Halima said that her husband and father-in-law were among the dead and that she had not heard from her three children since they had run away from the killers. At that point, there were 270 Muslims left in Bossemptele. Forty-eight hours later, only 80 Muslims remained at the mission — almost all women, children and people with disabilities.

In the interim, a convoy of commercial trucks had come through en route to Cameroon. Those strong enough took their chances: Parents abandoned children with disabilities; some men left their wives and kids. They were desperate to escape the nightmare that the Central African Republic has become for Muslims, who have paid with their lives for the Seleka’s sins.

For paper-thin Halima, who had stopped eating, dying seemed to be the only option left. “There is no one to help me,” she said, crying. “I did not have the strength to climb on the trucks, and no one helped me. I kept calling after them to take me, but they left without me.”

All around us were the abandoned. Ten-year-old Mikaila and his sister, Zenabu, 15, both paralyzed by polio, said that their parents had dropped them at the Catholic Mission after a January attack and had not returned. Al-Hadj Towra, 70, his hands and feet wasted away from leprosy, had been left bedridden in his home, where a priest found him two days later.

The only force in this town that seems able to protect vulnerable Muslims from the anti-balaka are the courageous Catholic priests and nuns of the Bossemptele mission. Father Bernard Kinre said he spent days looking for Muslim survivors after the January massacre. He embraced Iyasa, 12, a polio survivor, and recounted how he found the boy abandoned by a nearby river. Five days after the attack, Iyasa was still in shock. “He tried to run away from me when we found him,” Kinre said. “He thought I was the anti-balaka who came to kill him.”

The Catholics’ humanity, courage and leadership stand out amid the slaughter. They are virtually alone in trying to protect the vulnerable. France and the African Union have deployed thousands of peacekeepers; the United States and other governments have provided support to the peacekeeping mission. But their efforts to protect civilians pale next to the bravery exhibited by these clergy.

Most places I and a videographer visited in a five-day journey were emptied of Muslim residents, despite the presence of peacekeepers in many towns. The outnumbered French and African Union forces have often acted too passively, unable to prevent the looting and burning of homes and businesses that have forced Muslims to seek opportunities elsewhere.

Entire Muslim communities have disappeared. Baoro was once home to at least 4,000 Muslims and more than a dozen mosques. Now there are none. The last Muslims of Boali, where the local Catholic priest sheltered 700 in his church, left for Cameroon. The last Muslims of Yaloke, where more than 10,000 had lived, left for Chad.

The last Muslim in Mbaiki, Saleh Dido, was murdered recently by the anti-balaka, his throat slit as he tried to find shelter with police. Three weeks earlier, interim President Catherine Samba-Panza and the French defense minister, Jean-Yves Le Drian, had visited Mbaiki and declared it a “symbol of living together and reconciliation.” Now, its 4,000 Muslims are gone, their mosques destroyed.

Those who remain, such as the 4,000 or so Muslims in Boda, live in constant fear. Muslim families there are starving to death. A rake-thin man, Al-Haj Abdou Kadil, said he buried two of his children, Mousa, 3, and Mahamat, 4, the day before we met. They had died from hunger, and his wife was too weak to speak.

Too few peacekeepers were deployed too late; the challenge of disarming the Seleka, containing the anti-balaka and protecting the Muslim minority was underestimated. Now, their only option seems to be to facilitate evacuations, at the risk of contributing to the ethnic cleansing they were deployed to prevent.

Over the past six months, the Obama administration has provided financial and logistical support to the African Union mission and more than $45 million in humanitarian assistance. It should do more to halt the violence of the anti-balaka, starting with making clear its support for a U.N. Security Council resolution that would authorize a peacekeeping mission with the resources, expertise and will necessary to protect civilians.

Without this basic security, it will be even more expensive and painful to rebuild the Central African Republic.