BAMAKO - Close to 2000 people, about half of them children, have fled northern Ivory Coast into Mali recently to escape unrest amid fighting over a disputed election, officials said.

The refugees, who arrived over the past three days, include Malians, Ivorians and other Africans, a local government official in the southern city of Sikasso said.

"In 72 hours, we have counted close to 2000 people, Malians, Ivorians and other Africans, who have left Ivory Coast through the north for Mali, passing through the Sikasso region," Abass Konare said.

The north of Ivory Coast is under the control of forces backing Alassane Ouattara, who is internationally recognised as president, but is unable to fully take power because rival Laurent Gbagbo refuses to step down.

Fighting between forces loyal to either side has picked up since the disputed November 28 election, raising fears of a return to civil war.

"Among the people arriving on Mali territory, there are more than a million children who are accompanied by their parents," a doctor said.

"The children were vaccinated for free against polio in the Malian area of Kadiolo," Dr Lamine Camara said.

Many had chosen to stay in Kadiolo, about 15km from the Ivory Coast border, Camara said.

The UN refugee agency said last week that up to a million people might have been displaced by the fighting in Ivory Coast, including in the commercial capital Abidjan.