The United Nations refugee agency, UNHCR, says it's racing against time to save civilians fleeing attacks by rebels in the east and north of Sierra Leone.

A senior UNHCR official, Soren Jessen-Petersen, told a news conference in the capital, Freetown, that more than two-hundred-and-forty-thousand people had now fled to refugee camps in Guinea and Liberia over the past few weeks.

He said they'd suffered what he called barbaric and unequalled atrocities at the hands of the rebels.

The former military regime in Sierra Leone was ousted four months ago, but forces loyal to it are still fighting troops of the West African intervention force in the north and east of the country.