BANGKOK - More than a thousand anti-government protesters took to the streets of Bangkok on Sunday (July 18), defying a ban on mass gatherings to voice their grievances with Thailand's handling of the pandemic and demanding the resignation of Prime Minister Prayut Chan-o-cha, who heads the country's 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.

Protest organisers called for the protest to end just after 6 pm (7pm Singapore time), Reuters reported, but a stand-off between the police and a large group of protesters continued for several more hours.

Police dispersed the crowd just before the start of a 9 pm curfew that is in force in the Thai capital.

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

Efforts to curb the virus surge have been hindered by insufficient vaccine supplies, coupled with concerns over the efficacy of the Sinovac shots that the authorities use as 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 also listed three demands. The first, for Mr Prayut to step down; second, to divert budget funds meant for the monarchy and military towards Covid-19 efforts; and lastly, for the government to stop using Sinovac vaccines and buy mRNA-based jabs 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 as he clutched one of the bags.

"The Covid-19 situation is proof that the government cannot handle the country well," he added.

Along the route, 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 government ban that started last Friday night, prohibiting mass gatherings. Offenders face a penalty of up to two years' jail or a 40,000 baht (S$1,655) fine, or both.

When asked if she was worried about police enforcement or the risk of getting Covid-19, merchandising officer Siriyakorn Jampatong, 24, who joined the march, 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.

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

Thailand on Sunday also extended Covid-19 restrictions, which include travel curbs, mall closures and a curfew from 9pm to 4am, to three more provinces from Monday (July 19).

These curbs are the strictest the nation has seen in the past year and had already been imposed in Bangkok and nine other provinces since last week. They are to be in place for all affected provinces until Aug 2.

Domestic flights to and from these high-risk provinces will also be suspended from Wednesday, with the exception of medical or emergency flights and those part of the tourism reopening programmes. Other domestic flights can only operate at half capacity.

On Sunday, Thailand reported a record 11,397 new cases, the third consecutive day it registered record numbers. It also had 101 new deaths, bringing the total number to 3,341 fatalities and 403,386 cases since the pandemic started last year.

The impact of the pandemic on livelihoods led one protester, who wanted to be known only by her nickname May, to turn up.

"I had to close my spa six months ago. I've no work now," said the 40-year-old.

Some businesses, such as spas and massage parlours, have been forced to close multiple times over the past year.

"We need freedom, we need democracy," said May.