A vendor at an Oshin eatery chain wraps chicken and rice for a customer with a message put up on the stall front offering a free meal to anyone made jobless as a result of the Covid-19 outbreak.

Thousands of migrant workers from Myanmar, Laos and Vietnam returned to their home countries after authorities reopened land borders which had been ordered shut to prevent the spread of Covid-19.

The government's temporary ban on cross-border travel between Thailand and neighbouring countries failed, as it was forced to reopen shuttered crossings to allow the growing number of migrant workers which had gathered at border checkpoints to cross, out of fear of causing a riot.

Most of the migrants worked in Bangkok, but decided to leave after the Bangkok Metropolitan Administration ordered businesses -- including shopping malls -- to close until April 12 as part of its effort to urge the public to stay home during the outbreak. Under the closure order, only supermarkets and food retailers at other markets are allowed to open, and restaurants can only offer take-outs to its patrons.

According to Bangkok Metropolitan Administration estimates, about 90% of those who left Bangkok over the weekend were migrant workers.

In Chiang Rai, the border was reopened after a group of about 100 workers from Myanmar arrived at the Mae Sai checkpoint -- which links to Tachileik in Myanmar -- only to find the border has been closed.

"We must go home, or we will starve to death in Bangkok," said a 28-year-old woman in the group who was recently laid-off due to the shutdown.

clockwise from top A vendor at an Oshin eatery chain wraps chicken and rice for a customer with a message put up on the stall front offering a free meal to anyone made jobless as a result of the Covid-19 outbreak. A worker at a car wash sprays disinfectant inside a car in the Pin Klao area of Bangkok, while alcohol gel is given free of charge to people at the Bang Chak petrol station on Sukhaphiban 1 Road. photos by Arnun Chonmahatrakool and Varuth Hirunyatheb

Their insistence forced the governor and immigration officials to grant them exemptions and allowed them to cross the border into Myanmar.

In Tak, more than 4,200 Myanmar workers were allowed to cross back into their country through the checkpoint at Mae Sot district.

Meanwhile, the atmosphere was tense at Sa Kaeo's Aranyaprathet checkpoint near Cambodia, where police had to prevent more than 400 Cambodian workers from protesting against the border closure.

The situation eased after Thai and Cambodian authorities decided to reopen the border temporarily to let the workers through.

A bus terminal in the Nakhon Phanom Municipality was also packed with stranded workers from Laos and Vietnam. They were later allowed to pass over the 3rd Thai-Lao Friendship Bridge to Khammouane province in Laos.

Meanwhile, Thai workers returning home from Bangkok are being told to go into 14-day self-isolation.

clockwise from top A vendor at an Oshin eatery chain wraps chicken and rice for a customer with a message put up on the stall front offering a free meal to anyone made jobless as a result of the Covid-19 outbreak. A worker at a car wash sprays disinfectant inside a car in the Pin Klao area of Bangkok, while alcohol gel is given free of charge to people at the Bang Chak petrol station on Sukhaphiban 1 Road. photos by Arnun Chonmahatrakool and Varuth Hirunyatheb

Checkpoints across the southern border with Malaysia have also been closed, although Malaysia had already ordered its borders closed earlier, following reports of Covid-19 cases linked to a mosque event in Kuala Lumpur this month.

Malaysia's nationwide lockdown has also driven Thai workers to return home. However, sources said, many failed to comply with the quarantine requirement.