The exodus of tens of thousands of Muslims from Central African Republic amounts to "ethnic cleansing", Amnesty International has said, warning that the sectarian bloodshed now under way despite the presence of thousands of peacekeepers is a "tragedy of historic proportions".
Their report on Wednesday comes as United Nations secretary-general Ban Ki-moon expressed fears that the violence ravaging Central African Republic could ultimately divide the country into a Muslim north and a Christian south as "the sectarian brutality is changing the country's demography".
"We cannot just continue to say 'never again'. This we have said so many times," Mr Ban said late on Tuesday. "We must act concertedly and now to avoid continued atrocities on a massive scale."
More than 1,000 people have been killed since sectarian fighting erupted in early December and nearly one million in this country of 4.6 million have fled their homes.
The country's Muslim minority, about 15% of the population, has come under growing attack not only from Christian militiamen but also from mobs of civilians who have carried out public killings on a nearly daily basis in recent weeks. In most cases, the bodies of Muslim victims were mutilated and sometimes dragged through the streets or set on fire.
For months, UN and French officials have warned that a genocide could be looming in Central African Republic, and Amnesty's use of the term "ethnic cleansing" is among the strongest language invoked yet to describe the inter-communal violence now afflicting the country.
Amnesty International said that while it is a big step to use the term, it is justified "given the level of violent and purposeful forced displacement we've been seeing", said Joanne Mariner, senior crisis adviser for the organisation in Bangui, the capital of Central African Republic.
"The exodus of Muslims from the Central African Republic is a tragedy of historic proportions. Not only does the current pattern of ethnic cleansing do tremendous damage to the Central African Republic itself, it sets a terrible precedent for other countries in the region, many of which are already struggling with their own sectarian and inter-ethnic conflicts," the report said.
The wave of violence against Muslim civilians is being committed by Christian militiamen known as the anti-Balaka, or anti-machete, who stepped up their attacks as a Muslim rebel government crumbled in January. Rights groups at the time warned that the Muslim minority would be especially vulnerable to retaliatory attacks as many Christians blamed them for supporting the brutal Muslim regime of the Seleka rebels who seized power in March 2013.
Some of the attacks have taken place in front of peacekeepers who were unable to halt the bloodshed. In one highly publicised case, Burundian peacekeepers withdrew from the scene as a frenetic mob of soldiers from the national army stomped and stabbed a suspected Muslim rebel to death.
In recent days, thousands of Muslims have climbed aboard trucks destined for neighbouring Chad, a predominantly Muslim country whose soldiers have provided armed protection to the refugee convoys.
Muslim victims have been buried within 24 hours, and with violence sending survivors fleeing for their lives it has been nearly impossible to determine how many have died nationwide since sectarian bloodshed erupted in early December when the Muslim Seleka government began weakening. Amnesty said it alone had been able to document the deaths of more than 200 Muslims.
Some of those killed lost their lives even as they tried in vain to reach safety in the neighbouring countries of Chad or Cameroon. At least 20 Muslims were killed last month as a group tried to flee the town of Bouar.
"The mass killing of civilians, destructions of homes, businesses and mosques and other means used by the anti-Balaka to 'ethnically cleanse' the Central African Republic of its Muslim population constitute crimes against humanity and war crimes," Amnesty said.
Their concerns were echoed by Human Rights Watch, which has also been documenting the violence and has helped get Muslims to safety in many circumstances. The group said that the major gold trading centre of Yaloke had previously been home to 30,000 Muslims and had eight mosques before fighting erupted. As of early February, just one mosque remained and fewer than 500 Muslims were still in town - under the protection of French peacekeepers.
"Whether the anti-Balaka leaders are pursuing a deliberate policy of ethnic cleansing or exacting abusive collective punishment against the Muslim population, the end result is clear: the disappearance of longstanding Muslim communities," said Peter Bouckaert, emergencies director at Human Rights Watch.
Rupert Colville, spokesman for the UN High Commissioner for Human Rights, admonished the anti-Balaka for inciting violence but stopped short of calling it "ethnic cleansing".
"I don't know if I would characterise it as ethnic cleansing but clearly the situation which wasn't entirely along religious lines initially increasingly has become very much so," he said.
Former coloniser France has sent 1,600 troops to help stabilise the country, and there are nearly 6,000 peacekeepers from African countries on the ground now.
Mr Ban announced on Tuesday that he is sending assistant secretary-general for peacekeeping Edmond Mulet to the country to consult with the African Union about possibly transforming the African force there into a UN peacekeeping force. He has also asked France to consider deploying additional troops.
But Mr Ban cautioned that even if the change to a UN peacekeeping force "looks increasingly necessary, it would take time for it to happen". Normally, it takes at least five or six months to get a UN peacekeeping force - in this case probably at least 10,000 troops - on the ground.