A coronavirus outbreak linked to a seafood market in Thailand surpassed 1,000 cases on Tuesday, as authorities weighed whether to introduce a wider lockdown.

Thailand has been on tenterhooks since Thursday following the positive virus test of a 67-year-old prawn seller from Mahachai market, Samut Sakhon province, about 40 minutes southwest of Bangkok.

As of early Tuesday morning, there were 1,063 confirmed positive cases out of 6,156 tested -- a major outbreak for a country which previously had 4,300 infections.

The majority of the new cases are workers from Myanmar, who toil on shrimp boats and in processing factories linked to the multi-billion-dollar Thai seafood industry.

Migrant Workers Rights Network coordinator Suthasinee Bik said Myanmar workers in quarantine were feeling anxious and stressed.

"They want people who have been infected to be separated from everyone else. It's a very crowded area," Suthasinee told AFP.

Initially, they did not have enough food but supplies were now sufficient, according to the rights group.

Samut Sakhon governor Veerasak Vijitsaengsri said the infection rate linked to the market is at about 27.91 percent but previously was 40 percent.

"We are seeing the light at the end of the tunnel," he told reporters.

The market and its vicinity have been on lockdown since Saturday with the thousands living there barred from leaving.

Thai deputy prime minister Prawit Wongsuwan said authorities were yet to make a decision on further lockdown measures and the fate of New Year's Eve countdown celebrations was also undecided.

"The prime minister will monitor the situation for a week. If it becomes more serious, it is necessary. We have to think about the majority," he told reporters.

Myanmar, which has registered more than 115,000 infections and shares a porous 2,400-kilometre (1,500-mile) border with Thailand has long been seen as the kingdom's Achilles' heel in the fight against coronavirus.

Thailand's tally of known infections was 5,716 as of Tuesday.