Soldiers stand guard against anti-government protesters outside the National Broadcast Services of Thailand (NBT) television station in Bangkok May 9, 2014.
Thai police fired teargas on Friday at royalist protesters bent on bringing down a caretaker government after a court threw Prime Minister Yingluck Shinawatra out of office and an anti-graft agency indicted her for negligence.
Yingluck's Puea Thai Party still runs the interim government and is hoping to organize a July 20 election that it would probably win, but the protesters want the government out, the election postponed and reforms to end the influence of Yingluck's brother, former premier Thaksin Shinawatra.
Protest leader Suthep Thaugsuban, speaking to supporters in a city park, urged them to rally outside parliament, the prime minister's offices and five television stations to prevent them being used by the government.
"We will sweep the debris of the Thaksin regime out of the country," said Suthep, a former deputy premier in a government run by the pro-establishment Democrat party.
Thaksin, a former telecommunications tycoon, is vilified by his enemies in the royalist establishment as a corrupt crony capitalist. But he won the unswerving loyalty of legions of rural and urban poor with populist polices when he was prime minister from 2001 until he was ousted in a 2006 coup.
He lives in exile to avoid a 2008 jail sentence for abuse of power but has been the guiding hand behind his sister's government.
By mid-morning, Suthep had led one group of flag-waving protesters to Government House, the official offices of the prime minister but which have been empty since January. He said protesters would camp outside overnight.
Trouble flared at another protest site when police fired teargas at a crowd of several hundred trying force their way into a police compound housing a government security group in the north of Bangkok.
The Erawan Medical Centre, which monitors hospitals, said four protesters were taken to hospital after inhaling teargas.
"That puppet Yingluck is gone but our work is not over," Pornprasert Chernalom, 39, who owns a small business in Samut Sakhon province, west of Bangkok, said earlier.
"The illegitimate Thaksin cabinet remains in power. Our next step is to give power back to the people."
Some protesters held pictures of Thaksin and Yingluck with their faces crossed out. Others held banners that read: "Love Thailand, eradicate the Thaksin regime".
Tens of thousands of the Shinawatras' "red shirt" supporters, angered by Yingluck's ouster, are also on their way to Bangkok for a rally on Saturday. They are clinging to the hope that the interim government will win the July election and bring the Shinawatras' party back to power.
The prospect of rival protesters in the capital over the weekend has raised fears of trouble. Both sides have armed activists in their ranks.
Twenty-five people have been killed since the anti-government protests began in November.
About 21,000 police and troops have been deployed in the capital, authorities said, but there was little security presence on the streets on Friday.
More trouble would deepen worry about Southeast Asia's second-largest economy which is already teetering on the brink of recession amid weak exports, a year-long slump in industrial output and a drop in tourism, presided over by a caretaker government with curtailed powers. Consumer confidence fell to its lowest level in more than 12 years in April.
The anti-graft agency indicted Yingluck for negligence on Thursday - a day after the Constitutional Court threw her out of office - in connection with a rice-subsidy scheme under which the state paid farmers way above market prices for their crops.
The scheme, a flagship policy of Yingluck's administration, was aimed at helping her rural supporters. But the government could not sell much of the rice it quickly stockpiled and was unable to pay many farmers.
If Yingluck is found guilty by the Senate, she could be banned from politics for five years. Several other members of the family and about 150 of Thaksin's other political allies have been banned for five-year terms since 2007.
Yingluck dissolved parliament in December and called a snap election but the main opposition party boycotted it and anti-government activists disrupted it so much it was declared void.
Yingluck and the Election Commission agreed last week a new ballot should be held on July 20, but the date has not been formally approved.
Thaksin or his loyalists have won every election since 2001.
The anti-government protesters say Thaksin buys elections. They want to change the electoral rules before new polls to try to stop his party winning again.