Supporters of Yingluck Shinawatra have begun streaming into western Bangkok for a protest against her removal as Thailand's prime minister and attempts by opponents to sweep the remnants of her government from power.
The gathering of the pro-government supporters on Saturday came a day after anti-government protesters began laying siege to television stations and state offices to press authorities to install a non-elected prime minister by Monday.
Jatuporn Prompan, who heads the pro-government Red Shirts staging the rally, said on Saturday that "as long as the country's democracy is not safe, we will be here".
Jatuporn warned that his side would "escalate our fight immediately" if the anti-government protesters' demands were met. He said, however, that the Red Shirts did not "wish to see people killed or hurt along the way".
The competing rallies were being held several dozen kilometres apart, but still raised concerns about violence. Jatuporn said "each side should take care of their own supporters" and avoid confrontation.
The constitutional court this week forced Yingluck from government for abuse of power for transferring a senior civil servant in 2011 to another position.
Niwattumrong Boonsongpaisan, the deputy prime minister, was named soon after as her replacement.
Yingluck dissolved the government in December after an election that was boycotted by the main opposition party, the Democrats.
A new election had been planned, but no date had been agreed with the country's electoral commission.