* MSF says receiving 15-20 wounded a day at airport site
* MSF warns of possible epidemics at airport site
* Displaced sheltering under cardboard, food scarce
By Paul-Marin Ngoupana
BANGUI, Dec 29 (Reuters) - More than 100,000 people displaced by inter-religious violence in Central African Republic are sheltering at a makeshift camp at Bangui airport, a medical charity said on Sunday, calling for urgent aid.
Medecins Sans Frontiers (MSF) said it was receiving between 15 and 20 wounded a day at the site from fighting in the riverside capital, where the deployment of French and African peacekeepers in early December has failed to halt violence.
Attacks by Muslim Seleka rebels, who seized power in March, and Christian militias have killed more than 1,000 people and displaced an estimated 400,000 in Bangui this month.
MSF said the airport camp, which stretches for kilometres beside the runway, lacked proper sanitation as well as supplies of food and water as U.N. agencies have failed to keep pace with the scale of the problem.
"If nothing is done in the next two weeks there is a risk of an epidemic breaking out," said Lindis Hurum, MSF coordinator at the airport camp. "MSF demands an increase in the emergency actions being taken by humanitarian agencies."
Without proper infrastructure at the camp, thousands of families are sheltering from the tropical sun under cardboard boxes or makeshift tents made of blankets tied to sticks.
Despite the conditions, a spike in violence in recent weeks has driven tens of thousands of people to airport, which is patrolled by Burundian soldiers from the African Union peacekeeping force (MISCA) and lies next to a French military base. French troops in armoured vehicles guard the main gates.
"We are short of everything here. Food is scarce," said Samuel Degoto, 49, a teacher, who fled from his home in northern Bangui with his wife and seven children, carrying only a few bags. "If nothing is done before the next crisis strikes, there will be a catastrophe."
The United Nations launched an appeal on Friday for $152 million to help meet emergency humanitarian needs such as drinking water and sanitation in makeshift camps in the former French colony. It estimates that more than 800,000 people are displaced across the country as a whole.
Bangui was mostly calm for a second day on Sunday, aside from some isolated looting. An attempt by Christian youths from the northern Boy-Rabe neighbourhood to attack Muslims in the nearby Miskine district was blocked by French peacekeepers, a Reuters witness said.
The 'anti-balaka' militia have targeted Muslims they say have supported Seleka during months of looting and killing since it seized power in March. With many Seleka gunmen coming from Chad, its citizens in particular have been singled out, prompting their government to organise flights and convoys this week to bring them home.
Chad says it has evacuated some 4,000 of its citizens over the last week.
Many say the bloodshed has little to do with religion in a nation where Muslims and Christians had long lived in peace. Instead, they blame a political battle for control over resources in one of Africa's most weakly governed states.
French President Francois Hollande told U.N. Secretary Ban Ki-moon by telephone on Friday he wanted greater U.N. involvement in Central African Republic. Ban is preparing a proposal for a possible U.N. peacekeeping mission. (Writing by Daniel Flynn; Editing by Matthew Tostevin)