An anti-government protest leader has said the movement is ready to negotiate with Thailand's government to the violence in the capital.

However, Nattawut Saikua said there would only be a deal if troops were immediately withdrawn from Bangkok's streets.

At least 25 people have been killed in three days of fighting in Bangkok.

The Thai army has struggled to end weeks of increasingly violent protests by 'Red Shirt' demonstrators seeking fresh elections.

Mr Nattawut said the Red Shirts' only other condition to enter into dialogue was for representatives of the United Nations to moderate talks.

He said: 'We want the UN to moderate it because we do not trust anyone else. There is no group in Thailand that is neutral enough.

'We have no other condition. We do not want any more losses. We call on the government to cease fire and pull out troops. We are ready to enter a negotiation process immediately.'

The comments came minutes after the Thai government moved back from imposing a curfew in Bangkok.

Earlier, Prime Minister Abhisit Vejjajiva said a curfew was a possible step to restore order in the city of 15m people.

The government's immediate response to the offer was that no conditions should be attached to negotiations.

'If they really want to talk, they should not set conditions like asking us to withdraw troops,' said Korbsak Sabhavasu, the prime minister's secretary-general.

'It's a positive sign but if there is going to be a talk, there has to be more detail. But they cannot make demands if they want to negotiate.'

Protestors barricaded in camp

At least 5,000 protestors remain in a camp in the city, where they are barricaded behind walls of tyres, poles and concrete.

The army has set up a perimeter fence around the camp to try to stop more protestors reaching the base.

The government has called on women and the elderly to leave the camp by Monday afternoon.

It has asked independent organisations, such as the Red Cross, to help coax people out of the camp.

Troops have fired live rounds at protestors over the last three days after the army decided to allow soldiers to shoot if protestors came within 36 metres of army lines.

The government is to extend a state of emergency to five more provinces, because it fears that unrest in the capital could spread.

Several embassies have issued warnings to tourists not to travel to the city.

The US Embassy has offered to evacuate families and partners of US government staff based in Bangkok on a voluntary basis.