Authorities have prepared hundreds of police ahead of a planned rally on Tuesday involving a convoy of cars meeting in the centre of Bangkok.
Police have readied 750 officers to deal with the planned car protest on Tuesday and warned that all public gatherings were currently illegal under the Covid-19 emergency rules.
Last weekend, more than a thousand anti-government protesters clashed with police.
Protest leaders who had spent time in jail over previous demonstrations and been released on bail have gone back into custody in recent days.
The protest movement has been regaining momentum amid growing public anger about Prime Minister Prayut Chan-o-cha's handling of the country's worst wave of Covid-19 infections and with the economy taking a new battering.
