The government has been suffering massive defeats one after another - that's the reason why the Defence Ministry sought to create confusion

Dina Nath Sharma, rebel spokesman

A senior member of the rebels' politburo, Dina Nath Sharma, told the BBC that an apparent truce offer from rebel leader Prachanda was "a conspiracy hatched by the Nepalese Government".

"We are not in favour of a ceasefire because we are winning this war," Mr Sharma said, in an exclusive telephone interview with the BBC Hindi Service.

His comments came as tens of thousands of people marched in the Nepalese capital, Kathmandu, to protest against the Maoist violence.

The demonstration, organised by the kingdom's main political parties, called on the government and the rebels to seek a negotiated solution to a conflict which has cost 4,000 lives over the last six years.

40 rebels 'killed'

Mr Sharma rejected official suggestions that hundreds of rebels had been killed in recent battles in western Nepal.

The rally was one of the biggest in recent years

"Our people are safe. There were only 11 casualties, which the government made into 500. There is no truth in the government claim."

Mr Sharma, who was speaking from the Indian capital, Delhi, said a fuller statement would come from Prachanda later on Friday.

In its latest account of the fighting, the government says 40 rebels were killed in overnight clashes with the secuity forces in western districts.

Casualty figures are impossible to verify as the media and human rights groups have been barred from the conflict zone.

'Can't trust' rebels

Peace hopes rose on Thursday when a statement purporting to come from Prachanda was emailed to newspapers in the capital, Kathmandu.

Unless they lay down arms and denounce violence, we can't trust them

Prime Minister Sher Bahadur Deuba

It said a unilateral ceasefire would begin next Wednesday and last for a month.

Nepalese Prime Minister Sher Bahadur Deuba was swift to reject the offer, saying the rebels could not be trusted.

"They are not serious, they are not sincere, they have betrayed Nepal before," Mr Deuba told the BBC.

Security has been stepped up in Kathmandu

His government insists on a total rebel surrender before any negotiations.

A week ago, the rebels offered to resume peace talks.

Some observers detect desperation among them and a decline in their morale - but others argue they are merely buying time to re-organise.