GENEVA -- The United Nations and aid groups launched an appeal for $274 million Wednesday to help people who have fled the Central African Republic because of the sectarian conflict there, warning that the dire needs of hundreds of thousands of refugees can't be met with existing funds.

The appeal is separate from the $547 million that the global body asked donors for earlier this year to help some 600,000 people displaced inside the Central African Republic.

The UN refugee agency said that since December nearly 200,000 people have sought refuge in neighbouring countries, and that figure is expected to rise to over 360,000 by the end of the year.

"The mainly women and children fleeing atrocities in CAR are arriving in neighbouring countries deeply traumatized, many wounded by machete or gunshot, malnourished and exhausted from weeks of walking and hiding," the agency said.

"All the agencies working in the region are dramatically underfunded," the UN High Commissioner for Refugees, Antonio Guterres, told diplomats in Geneva.

Guterres said his agency is already spending three times as much as it has received so far. "This cannot be sustained," he said.

The money sought by the UN refugee agency and 14 other humanitarian organizations will be used to pay for shelter, food, water, sanitation, health care, education and basic needs.

Last week, the UN Security Council authorized a nearly 12,000-strong peacekeeping force to bolster French and African Union troops that have been deployed to protect civilians throughout the vast country.

The Czech Republic's military can offer up to 250 servicemen for the mission, Defence Ministry spokesman Jan Pejsek said Wednesday. The plan will be presented to the government for approval in the next few weeks, he said. During a recent visit to Prague, UN Secretary-General Ban Ki-moon appealed for troops to bolster the UN mission.