British troops intervened to take up positions around Freetown

Although most of the UN troops taken hostage have now been freed, over 200 others - mostly Indian troops and a small number of unarmed military observers, including a British major - remain surrounded by rebels in the east of Sierra Leone and are effectively confined to their bases.

The top investigating team from UN headquarters in New York is travelling to government-held areas outside the capital.

Flying by helicopter because the roads are far too dangerous, the team will gather information about the tense stand-off between UN troops and rebels in the diamond-mining eastern region of the country.

The team is not expected to meet these isolated troops directly. UN officials in Freetown are careful not to describe the mainly-Indian soldiers as hostages, but they are surrounded by rebels and restricted to their bases.

Show of strength

UN and British hostage negotiators are believed to be in regular radio contact with the isolated units and talks with the rebels are said to be going smoothly.

Although this situation is of serious concern to the UN, the arrival of the investigating team also coincided with the most positive step the UN mission has made for months.

Around 500 combat-ready peacekeepers sought to reverse earlier setbacks by moving towards the rebel front line in a show of strength.