Emergency forces reported that more than 93 people, including 22 soldiers and police, were injured in the clashes as the tensions escalated in the biggest confrontation after weeks of mass rallies.
"The army will not kill Thais but we have to restore law and order," Sansern Kaewkamnerd, the army spokesman, said.
He said that two soldiers have been shot during clashes with demonstrators, many of whom support Thaksin Shinawatra, the ousted former prime minister.
Troops had been ordered to reclaim the Phan Fah bridge and Rajdumnoen Road area, near several government and army buildings in the Thai capital.
There were about 4,000 protesters, including women and children, left in the area and the troops had about 200 metres to clear before they get to the main stage, Sansern said.
Hundreds of troops also massed at a downtown protest site, apparently ready to move in, and the crowd was growing by the hour.
"This is an explosive situation but both sides know that violence, like what happened in Kyrgyzstan, is not an option," Supong Limtanakool, professor at Bangkok University, told Al Jazeera.
“The side that starts the violence will be condemned. Thaksin has a chance to show that he has the country’s best interests at heart, by reaching a negotiation with the government."
Thai troops earlier used water cannons to repel anti-government protesters from an army base in central Bangkok, local television reported.
The protesters stormed the base near the Phan Fah bridge in the Thai capital on Saturday but did not enter it, local PBS channel has reported.
Government forces maintained a heavy presence at the television station they retook control of after claiming that the opposition channel was using it to incite violence.
The move came just hours after protesters had stormed the station and forced the reversal of an earlier decision to ban the channel.
The protesters have warned they will launch serious retaliation against the government but Abhisit Vejjajiva, the prime minister, has vowed not to bend to their demands that he relinquishes power and calls for fresh polls.
"The prime minister does not rule out negotiation with them but in order to do that they need to respect law and order first."
|Violent clashes have caused injuries among protesters and security forces [Reuters]
Nattawut Saikua, a red shirt leader, told a cheering crowd on Friday night at the commercial district rally site that the routing of the troops at the station was "a major victory".
Nattawut is one of some two dozen red shirt leaders for whom arrest warrants have been issued. So far, none have been taken into custody.
The Thaicom Pcl satellite station, which relays the People's Channel signal via satellite, was founded by Thaksin.
Panitan Wattanagakorn, a spokesman for Abhisit, told Al Jazeera from Bangkok that the station was closed because it was airing misleading information that the government would use force to crush the people.
The authorities had taken over the channel on Thursday, triggering some 12,000 protesters to move to the station in the suburb of Pathum Thani, about 50km north of Bangkok, on Friday.
"The station is inciting violence and spreading false information and rumours to the detriment of the country"
Sansern Kaewkamnerd, Thai army spokesman
Sansern Kaewkamnerd, an army spokesman, said security forces stood down "because we did not want any loss of life or to hurt anyone".
More than 4,000 soldiers retook the satellite transmission complex late on Friday after Abhisit ordered that the People Channel be blocked again.
"The station is inciting violence and spreading false information and rumours to the detriment of the country," Sansern said.
On Wednesday, Abhisit's government declared a state of emergency, allowing it to impose curfews, ban public gatherings, censor media and detain suspects without charge for 30 days.