Tens of thousands of Muslims are fleeing to neighboring countries by plane and truck as Christian militias stage brutal attacks, shattering the social fabric of this war-ravaged nation.

In towns and villages as well as here in the capital, Christian vigilantes wielding machetes have killed scores of Muslims, who are a minority here, and burned and looted their houses and mosques in recent days, according to witnesses, aid agencies and peacekeepers. Tens of thousands of Muslims have fled their homes.

The cycle of chaos is fast becoming one of the worst outbreaks of violence along Muslim-Christian fault lines in recent memory in sub-Saharan Africa, tensions that have also plagued countries such as Nigeria and Sudan.

The brutalities began to escalate when the country’s first Muslim leader, Michel Djotodia, stepped down and went into exile last month. Djotodia, who had seized power in a coup last March, had been under pressure from regional leaders to resign. His departure was meant to bring stability to this poor country, but humanitarian and human rights workers say there is more violence now than at any time since the coup.

“Civilians remain in constant fear for their lives and have been largely left to fend for themselves,” Martine Flokstra, emergency coordinator for the aid agency Doctors Without Borders, said in a statement Friday, adding that the violence had reached “extreme and unprecedented” levels.

On Friday, thousands of Muslims hopped aboard trucks packed with their possessions, protected by soldiers from Chad, and drove out of Bangui, as Christians cheered their departures or tried to loot the trucks as they drove through Christian areas. At least one Muslim man, who fell from a truck, was killed by a mob. Meanwhile, thousands more Muslims huddled at the airport in a crowded hangar, waiting to be evacuated.

“They are killing Muslims with knives,” said Muhammed Salih Yahya, 38, a shopkeeper, making a slitting motion across his throat. He arrived at the airport Wednesday from the western town of Yaloke with his wife and five children. “I built my house over two years, but the Christians destroyed it in minutes. I want to leave.”

Christians have also been victims of violence, targeted by Muslims in this complex communal conflict that U.N. and humanitarian officials fear could implode into genocide. Several hundred thousand Christians remain in crowded, squalid camps, unable or too afraid to return home.

But attacks on Muslims in particular are intensifying, aid workers said.

Djotodia’s departure weakened the former Muslim rebels, known as Seleka, who carried out deadly attacks on Christians after they grabbed power in March, prompting the birth of Christian militias called the anti-balaka, or “anti-machete” in the local Sango language. The armed vigilantes have used the power vacuum to step up assaults on Muslims.

Now in disarray, the Seleka are no longer able to protect Muslims from the Christian vigilantes. The roughly 6,500 French and African troops authorized by the U.N. Security Council to intervene have been unable to stop the violence.

“In the northwest and in Bangui, we are currently witnessing direct attacks against the Muslim minority,” Flokstra said. “We are concerned about the fate of these communities trapped in their villages, surrounded by anti-Balaka groups, and also about the fact that many Muslim families are being forced into exile to survive.”

Fleeing to Chad

According to the International Organization for Migration (IOM), more than 60,000 people, most of them Muslim, have fled to neighboring countries since Dec. 5, when violence erupted after an uprising by the Christian militias and former government soldiers. The number of departures escalated after Djotodia’s resignation. Muslims make up roughly 15 percent of the country’s 4.5 million people.

Most have fled to Chad and Cameroon, while others have gone to Nigeria, Niger and Sudan, according to IOM statistics. The numbers include foreigners who work in the Central African Republic as well as citizens. In this region, people often have social and economic ties across borders. Many families here, for example, have relatives in Chad, Cameroon and other neighboring nations.

IOM officials are concerned about those leaving. The vast majority, roughly 50,000, are headed to Chad, a mostly Muslim country that is also among the poorest in the world.

“What kind of support will they get from the Chadian authorities? Are they going to be able to reinsert themselves into society there?” said Giovanni Cassani, the emergency coordinator for IOM. “50,000 is a small town. And there is more on the way, and there will be more, unless the situation improves here.”

The Central African Republic, Cassani said, is already reeling from the economic shock of Muslims departing. Many are traders and shopkeepers who imported staples. They also ran the meat industry. “It’s going to have a massive effect on society here,” Cassani said. “Prices are going up. . . . It’s been extremely difficult to find beef in the capital.”

Many of the clashes have occurred in northwestern towns. In a village called Bozoum, 2,500 Muslims fled Wednesday, according to Doctors Without Borders. And Bouar, a Muslim town of 8,000 people, “remains effectively imprisoned” by anti-balaka militias, according to the agency.

Homes looted, taken apart

In Bangui, the capital, Chadian special forces and former Seleka rebels guarded the convoy of trucks carrying Muslims out of the city toward the Chadian border. The Muslims were picked up at the airport, at mosques and from an area called Kilo 5, one of the capital’s last remaining Muslim enclaves. In some cases, French and African soldiers had to fend off looters. A few trucks had to be abandoned.

The man who fell off one of the trucks was viciously slain by a mob that cut off his genitals and hands, said Peter Bouckaert, emergencies director for Human Rights Watch.

“The French keep trying to say the situation is stabilizing, but it actually isn’t,” Bouckaert said. “The only areas that are stabilizing are areas where all the Muslims are gone.”

Only two weeks ago, Bouckaert said, the Muslim neighborhood of Miskine was untouched by the anti-balaka. Today, the area is deserted, mosques and Muslim homes looted and taken apart brick by brick. About 10,000 Muslims lived in the town of Bossangoa in December, he added. Only a few hundred are left.

At the airport, Muhammad Abdirahman, 62, was waiting to leave. His village, Jbawi, had been burned down by the anti-balaka and nearly everyone was dead, he said. Fortunately, he had left with his wife and 12 children before the massacre, and arrived at the airport last week. Originally from Chad, he has lived here for the past 50 years.

“I don’t even know Chad,” he said. “But what can I do? If I stay, the Christians will use every opportunity to kill me and my family.”