The head of the UN military observer mission in Sierra Leone, Francis Okello, says the regional peacekeeping force, ECOMOG, has launched a counter offensive against rebels who have been gaining on the capital in recent weeks.

In the first confirmation from the UN of the counter offensive, Mr Okello said the Nigerian-led force was attacking rebel positions in Lunsar one-hundred and twenty kilometres east of the capital Freetown.

Reliable sources say Nigerian Alpha jets strafed rebel positions around Lunsar.

The BBC West African Correspondent says the UN views the situation in Sierra Leone seriously because of the potential of the conflict to destabilise the region