Emergency evacuations of the first of thousands of foreigners stranded in the conflict-ridden Central African Republic (CAR) are due to begin.
The International Organization for Migration (IOM) said it would start airlifting 800 Chadians from the capital Bangui on Saturday.
Some 33,000 Africans from neighbouring countries needed urgent help, it said.
CAR's interim President Michel Djotodia resigned on Friday over the fighting between Muslim and Christian militia.
Mr Djotodia, CAR's first Muslim leader, seized power last year. Since then 20% of the population have been forced to flee the violence.
The BBC reports that at least 1000 people have died since the clashes broke out in December.
The African Union now has some 4000 peacekeepers in the country and France has deployed 1600 troops to try to restore peace.
The UN earlier warned of an impending humanitarian disaster.
The IOM said it had received requests for assistance from Chad, Niger, Mali, Sudan and the Democratic Republic of the Congo to evacuate thousands of their nationals.
A total of over 60,000 migrants from neighbouring countries had asked for assistance from their embassies, said Carmela Godeau, IOM's West Africa director.
Nearly 27,000 have already been evacuated by their governments.
Further clashes reported
Further clashes have been reported in the Central African Republic.
There was shooting in parts of the capital, Bangui, between Christian militias and the mainly Muslim Seleka movement, which seized power under Mr Djotodia last March.
French peacekeepers were also involved in exchanges of fire.