The United Nations on Tuesday reported that violent unrest in Bangui has forced some 210 000 people from their homes in the past two weeks alone.
"The situation is very serious and appears to be worsening," UN refugee agency spokesperson Adrian Edwards said.
About 210 000 people fled their homes in Bangui after fresh fighting broke out in the strife-torn country on December 5, he said.
On Monday, UNHCR staff came across some 40 000 people who had fled between December 5 and 6 and had been hiding in an area near Bangui that had been out of reach of aid workers.
Finding such large pockets of displaced people off the radar raises concerns about how many people may have been forced from their homes across the largely inaccessible country.
"We have visibility on the situation in parts of Bangui and Bossangoa [in the northwest] and some other areas, but there are large parts of the country where systematic understanding of the situation is very, very thin at the moment," Edwards said.
"We are worried … It's very, very violent."
The resource-rich but poverty-stricken majority Christian country has descended into chaos and sectarian violence since a March coup by mainly Muslim Seleka rebels.
After a fresh wave of violence two weeks ago, French troops deployed in a bid to stop communal strife that had sparked global alarm.
Some 600 people have been killed in the country in the last 11 days, and two French soldiers died in a gun battle.
Since the crisis began a year ago, more than 710 000 people have been displaced inside the CAR and over 75 000 have fled across its borders, according to the UNHCR.
So far, the arrival of the French troops does not seem to have stemmed the violence and lawlessness, Edwards said, stressing that "it has certainly not bottomed out yet."
Insecurity and food shortages have meanwhile spurred many women and children from the capital to flee across the Ubangi River to seek refuge in Zongo in the Democratic Republic of Congo.
More than 1 800 people crossed the border there, which is officially closed, at the weekend alone, bringing to nearly 4 000 the number of Central Africans who have arrived in the past two weeks, UNHCR numbers show.
The UN's World Food Programme had begun delivering aid to some 40 000 people camped out near Bangui airport Friday, but suspended operations the next day due to threats from a group of men wielding machetes, spokeswoman Elisabeth Byrs told reporters.
She said deliveries were due to resume on Tuesday.
Edwards meanwhile said another 5 600 people had been displaced in Bossangoa since December 5, and had joined more than 4 000 others already huddled together at an overcrowded local school.
"We continue to hear of attacks against Christians by former Seleka, with looting, killing and houses set on fire," he said, pointing out that another 40 000 people were holed up at the Bossangoa Roman Catholic church.
Meanwhile, Bangui residents say the French military deployed into neighbourhoods to flush out a Christian militia that had infiltrated the area at dawn.
Oscar Badou, who lives in the Fou neighbourhood, said Tuesday the militia encircled the area at about 4am, erecting barriers in order to prevent cars from circulating.
The Christian militia, known as anti-Balaka, was behind an attack on the capital earlier this month which set off a wave of violence that killed at least 500 people.
Badou says the militiamen tried to prevent people from going to work, to press the country's Muslim president to step down.
He said the militia fled into the hills after a French helicopter flew overhead and French troops in armoured personnel carriers began patrolling Fou's streets. – AFP, Sapa-AP