More than a thousand anti-government protesters took to the streets of Bangkok yesterday, defying a ban on mass gatherings to voice their grievances with Thailand's handling of the pandemic and to demand the resignation of Prime Minister Prayut Chan-o-cha, who heads the virus task force.

Police used water cannon and fired rubber bullets and tear gas as they tried to stop protesters from removing barriers along the marching route from the Democracy Monument towards Government House, where Mr Prayut works.

Thailand is fighting its deadliest Covid-19 wave to date, with daily figures hitting over 10,000 infections and exceeding 100 deaths.

Efforts to curb the virus surge have been hindered by insufficient vaccine supplies and concerns over the efficacy of the Sinovac shots, one of the primary vaccines in the national inoculation drive.

"Get out, Prayut!" chanted the masked crowd, as many turned up in unofficial protest colours of red and black, armed with gloves, face shields and sanitiser spray.

Protest leaders listed three demands: for Mr Prayut to step down; to divert budget funds meant for the monarchy and military towards Covid-19 efforts; and for the government to stop using Sinovac vaccines and buy mRNA-based vaccines instead.

Some in the crowd also held mock body bags made out of cloth, stuffed with hay and splashed with red paint.

"This represents the bodies of people who died from Covid-19," undergraduate Saharat Jantasuwan, 22, told The Straits Times. "The Covid-19 situation is proof that the government cannot handle the country well."

Protesters also conducted a mock execution with the "body bags" and set fire to a cardboard figure of Mr Prayut.

The march, organised by the Free Youth Group and its alliances, went against a ban prohibiting mass gatherings.

When asked if she was worried about police enforcement or the risk of getting Covid-19, merchandising officer Siriyakorn Jampatong, 24, said she feared for her future more. "The system has failed us. We must stand up and fight. If not, we will continue to live in fear," she said.

The protest marked the one-year anniversary of the first large-scale street protests led by youth groups demanding Mr Prayut's resignation, a new Constitution and a major reform of the monarchy.

Thailand yesterday also extended restrictions - which include travel curbs and a curfew from 9pm to 4am - to three more provinces from today. These curbs have been imposed in Bangkok and nine other provinces since last week.

Domestic flights to and from these provinces will be suspended from Wednesday, with the exception of medical flights and those which are part of the tourism reopening programmes.

Thailand has recorded 3,341 Covid-19 deaths and 403,386 cases so far.