A new outbreak of the coronavirus in Thailand reported in the middle of December is posing a new threat to the country.

Thailand had the coronavirus at bay for much of last year. After the government imposed a rigid countrywide lockdown in May the number of new local transmissions fell to zero where they remained for the next six months.

Thailand has reported more than  527 new infections - most of them migrant workers who were already quarantined and local health authorities said they were now restricting the movement of people around the country, CNA and other news organizations reported Wednesday.

Large areas of Thailand, including Bangkok, are now under lockdown prohibitions and authorities said they would also ban travel between virus-hit provinces except for goods and necessary travel. Checkpoints have been set up on main roads.

The new cases are linked to an outbreak detected in December at a shrimp market in Samut Sakhon, a coastal area southwest of the capital that is home to many migrant workers.

The new lockdown and the potential of tighter restrictions are expected to worsen the economic effects of the virus. Based on projections by the World Bank Thailand's economy was estimated to contract between 8.4% and 10.5% last year.

Thailand's pandemic coordinating council has warned that the number of new daily infections could balloon to more than 10,000 by later this month if health officials don't do more to contain the spread.

Meanwhile, Thailand's prime minister said Tuesday the government had ordered an additional 35 million doses of the AstraZeneca COVID vaccine - bringing its stocks to 63 million doses.

Thailand will also get its first batch of orders of vaccines from China's Sinovac Biotech next month - allowing it to start immunizing people with the highest risk of infections.