The UN Under Secretary General for Humanitarian Affairs, John Holmes, said the group led by Colonel Karuna should be disarmed as soon as possible to ensure safety and security for aid workers and people living in the area.

Mr Holmes' visit to Sri Lanka coincided with a ceremony marking the first anniversary of the murder of seventeen workers for a French charity (Action Against Hunger).

It happened during fighting between the Sri Lankan armed forces and the Tamil Tigers. (Nordic ceasefire monitors blamed the military -- an allegation the government rejected.)

Mr Holmes said investigations needed to be concluded rapidly and those responsible brought to justice.