29 people have now been killed during three days of fighting in the Thai capital - as Channel 4 News Asia correspondent Nick Paton Walsh believes the standoff is nearing its climax.
Fighting has continued to rage in two districts of Bangkok between government forces and red-shirt protesters who back the ousted prime minister Thaksin Shinawatra.
The clashes have left more than two hundred people injured.
Districts of Bangkok have been transformed into battlegrounds.
The most severe fighting has taken place in the city's Bon Kai area of Rama IV, a major link to the city's business district.
Eyewitnesses reported seeing troops and snipers firing at protesters, who hurled petrol bombs in retaliation.
A team working for Channel 4 News heard gunfire and loud bangs in the streets.
Five thousand protesters, including women and children, have barricaded themselves in an area surrounded by luxury hotels and shopping centres for six weeks.
Nattawut Saikai, a protest leader, today called for a ceasefire and talks moderated by the United Nations. "We do not want any more losses," he said.
However that plea was quickly rejected by the government. "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.
Eyewitness report: Nick Paton Walsh in Bangkok
Today it seemed to get nastier.
The live rounds became routine - the army sealing off more areas, declaring them "live fire zones": places where you can expect to get shot. The protestors expanded their field of influence - settling in it seemed to the north, in the area of Din Daeng, and opening an entirely new stage in the south, down near Klong Toy.
And today was when the idea of talks being the solution to this seemed to finally evaporate. What's left of the protests shattered and bickering leadership said they would talk if the UN was involved and the shooting stopped. The government - who, unsurprisingly, with an entire army at their call, realise they have the upper hand - said no. They demanded surrender, and told women and children to get out. We'll not see a curfew tonight, but we will perhaps tomorrow.
This is pushing itself to a close. We've seen the protestors so emboldened; they treat sectors of the city as their own. We've seen the government now so in awe of their own might, they say they don't want to talk.
One announcement today was key: tomorrow and Tuesday will be public holidays in the city. Stay at home people, the government say - they've got to bring this to a close. Loud blasts have filled the sky around our office block. The end of this feels like it is getting nearer.
Yesterday, the Prime Minster Abhisit Vejjajiva said taking military action against the Red-shirt protesters was the "only way" to end street battles which have destabilised the country's political process for six weeks.
But the Thai authorities have pulled back from their earlier threat of imposing a curfew in the city.
However a state of emergency has been imposed in twenty provinces on Sunday to allow security forces to control any unrest linked to violent protests in Bangkok, a government spokesman said.
The protesters are made up of mainly rural and urban poor who accuse the military-backed government of colluding with the loyalist elite to bring down previous Thaksin-allied governments.