A United Nations report says over $500m are urgently needed by the end of the year to carry out reconstruction work in Afghanistan.

The report, presented to the Afghan Support Group of donor nations meeting in Geneva, says the money is needed to help the returning refugees.

It warns that without outside help, the country may slip back to the control of the warlords.

The UN appealed last February for $1.6bn in humanitarian aid for this year - so far only half of the sum has been collected.

From the newsroom of the BBC World Service