Health officials checked visitors to a market in Chiang Mai, northern Thailand, after an explosion of Covid-19 cases linked to a fish market sparked panic across the country.

Officials have also confirmed that all of the 300 migrant workers at the market have tested negative from the check on Monday (December 21).

Footage shows officials scanning the market's visitors to ensure the safety of the market to prevent the spread of the virus in the province.

The area, close to the border with Myanmar and a busy region, has strong links to the Samut Sakhon seafood market on the outskirts of Bangkok, where at least 821 workers have positive for the virus in recent days. Around 90 per cent of them were asymptomatic.

The Burmese migrant workers have been banned from leaving the compound and locals have had to deliver supplies of fresh food and water to them. There are believed to be more than 1,000 workers trapped inside the market area, which includes hundreds of shabby homes.

It came as several people in neighbouring areas tested positive following recent trips to the market, sparking fears of a second wave erupting in the country, which has largely kept the pandemic under control.

Deputy governor of the province, Surasak Polyangsong, said the first case was found last Thursday and since then, more than 2,000 people have been tested.

He said that an estimated 10,000 tests on people living and working in and around the market would be carried out using mobile labs this week.

Schools near Samut Sakhon have been ordered to shut while commuters between cities were advised to work from home. New Year events in the capital Bangkok have also been cancelled.

Thailand - which closed its borders in March and has enforced mask-wearing - has so far recorded 5,716 cases of coronavirus and 60 deaths.