A series of coronavirus clusters among construction workers in Bangkok, including the first local cases of the variant first identified in India, has put a fresh spotlight on migrant labour rights as the country grapples with the deadliest outbreak so far.
Migrant workers have been crucial during Bangkok's decade-long construction boom, but they receive limited welfare from the government and their employers, advocacy groups say. Many live onsite in crowded dormitories to save money.
Health authorities last week detected the first 36 domestically transmitted cases of the highly infectious B.1.617.2 coronavirus variant among people in construction workers' accommodation in Bangkok.
City authorities have prohibited movement of workers at such camps after 11 were among 30 active clusters in the capital.
There are around 409 workers' camps around Bangkok where authorities say 62,169 workers live, about half of them migrant labour.
"Migrant workers are a group that society overlooks," Suthasinee Kaewleklai, Migrant Workers Rights Network (MWRN) coordinator in Thailand said.
"Many were not confident that they can come in for tests and not be arrested."
The International Organization for Migration estimates that there are 4 million to 5 million migrant workers in Thailand, many working in construction, manufacturing and seafood industries.
Workers from Myanmar were among those worst-hit by the previous coronavirus outbreak in December. The epicentre was Samut Sakhon, the province on the southwest side of Bangkok with a high concentration of migrant labourers.
The outbreak also saw a sharp rise in anti-Myanmar hate speech on Thai social media.
There are also concerns that illegal border crossings are undermining the country's strict quarantine system for arrivals in the country.
Authorities tightened border crossings at the weekend after three local cases were found of the Covid-19 variant first identified in South Africa, stemming from illegal entry from Malaysia into Narathiwat.
Another highly transmissible variant, known as B.1.1.7 and first detected in Britain, is believed to have entered Thailand via an illegal border crossing from Cambodia.
Nearly 33,000 illegal migrants have been arrested since July 2020, the defence ministry said.
The latest outbreak has accounted for nearly 80% of Thailand’s 132,213 cases and close to 90% of the 806 deaths recorded so far.