More than 860 new Covid-19 cases have been found at Simummuang Market in Pathum Thani, while Bang Kapi Market in Bangkok was also closed for three days.

The Public Health Ministry said on Wednesday that no new Covid-19 cases have been found from entertainment venue clusters, but a lot of people still contracted the virus from family members and from visiting crowded markets and public venues.

From Covid-19 testing at Simummuang Market between May 7 and 15, it was found that of 10,480 people who have been tested, 867 people or 8% of the test group were infected.

It was also found that 70% of the infected people are Thai citizens, while 30% are migrant workers.

Officers have ordered closed some sections of the market and also set up a 400-bed field hospital at the market to treat infected people. Another 400 beds will be added to the field hospital today.

The cause of the high infection rate was the fee gate at the market's public toilet.

The fee gate has since been removed and replaced with a hand sanitiser gel booth.

However, the opening of the field hospital at the market has drawn criticism, with many people calling it an inappropriate environment to treat Covid-19 patients.

Meanwhile, Bang Kapi Market was closed for virus containment until Saturday.