Soldiers take aim at anti-government protesters in Bangkok on Saturday. (Manish Swarup/Associated Press)

Thai troops clashed with anti-government protesters in Bangkok for the third day in a row, as the government declared a "live firing zone" close to the camp occupied by the Red Shirts.

Troops opened fire at protesters after they launched rudimentary missiles at the army. Protesters said they dragged away the bodies of three people from sidewalks who they say had been shot by army snipers.

"The situation right now is getting close to a civil war each minute," Jatuporn Prompan, a protest leader, told reporters. "Please don't ask us how we are going to end this situation, because we are the ones being killed."

Prime Minister Abhisit Vejjajiva made his first comments since violence erupted on Thursday, saying Thai forces are attempting to "restore normalcy" with a minimum of bloodshed. So far, at least 24 people have been killed and more than 194 have been injured.

"I insist that what we are doing is necessary," Vejjajiva said Saturday in a broadcast on national television. "The government must move forward. We cannot retreat because we are doing things that will benefit the entire country."

'Armed terrorists'

Abhisit said the protesters have "held the people of Bangkok hostage" and described them as "armed terrorists" who attacked security forces.

"Officers on duty have the right to defend themselves," he said.

Thousands of Red Shirt protesters, mostly rural poor, have occupied one of the capital's most upscale areas since March 12. Fighting since then has left at least 37 people dead. The three-square-kilometre zone is barricaded with tire-and-bamboo-spikes

On Saturday, soldiers unrolled razor wire across roads leading to Ratchaprarop — a commercial district north of the main protest site — area and pinned up Thai and English-language notices saying "live firing zone" meaning anyone who enters it, enters at their own risk.

Whole streets of Bangkok have been cordoned as the military brings in reinforcements from outside the capital.

The military claimed that cutting water and electricity to the red shirt camp is having an effect, with the number of protesters having dropped from 10,000 to 5,000.

During two consecutive nights of clashes this week, security forces fired rubber bullets, tear gas and live ammunition, while protesters seized army equipment and set fire to a police bus.

New elections

The Red Shirt demonstrators believe Abhisit's coalition government came to power illegitimately through manipulation of the courts and the backing of the powerful military. They are demanding he dissolve parliament immediately and call new elections.

The crisis had appeared to be near a resolution last week when Abhisit offered to hold elections in November, a year early. But the hopes were dashed after Red Shirt leaders made more demands.

Canada's Foreign Affairs Department on Friday announced the Canadian Embassy in Bangkok is temporarily closed to the public because of the fighting. The United States, Britain, Japan and the Netherlands closed their embassies on Thursday.

In another development, Nelson Rand, a Canadian journalist covering the anti-government protests in Bangkok, was recovering from his hospital bed in the Thai capital Saturday, a day after being struck by three bullets.

With files from The Associated Press