The closures are part of a raft of measures introduced by the government to help control the rising number of confirmed cases of the virus in the country. Bars, cinemas and entertainment centres will also be closed, and the Thai New Year holiday from April 13-15 will be postponed.
It has not yet been confirmed when schools will reopen, but the closure period is expected to last two weeks until March 31. The Ministry of Education says that "schools are encouraged to maximise online learning platforms" during this time.
According to Reuters, Ratchada Thanadirek, the government's deputy spokeswoman, said: "The cabinet approved that the Songkran holiday be postponed and schools closed."
A statement on the Shrewsbury International School website says: "Both Riverside and City Campus will be closed from Wednesday 18th March. Shrewsbury is still awaiting official confirmation from The Ministry of Education and will provide a further update on Wednesday 18th March.
"Online learning will start from Wednesday 18th March. School Principals and School Leaders will provide details shortly."
And head of school at Bangkok International Preparatory School, Duncan Stonehouse, told parents: "We believe that the Thai Government will review the closure of schools and universities every 15 days.
"Our primary concern is to protect our community and Bangkok Prep will, therefore, follow the directives of the Thai Government. During this period of closure, the teachers will provide all students with online lessons."
Brighton College (Bangkok) reassures parents, saying: "During any closure period we will continue managing the teaching and learning of our pupils. We will endeavour to ensure that children experience the familiar structure of the school day, with two way communication and feedback.
"We have already sent out information about how that will take place, to include registration and online lessons."
The news comes as Thailand confirmed 33 new cases of Covid-19 yesterday – the country's highest daily increase – which brings the total number of cases to 147.
International schools in Thailand follow directives from the Thai Ministry of Education, the Office of Private Education Commission (Opec), and the International Schools Association of Thailand (ISAT). Until now, these have included guidelines on precautionary measures such as self-quarantine, temperature checks and mass gatherings. Principals have been reassuring parents that while school is very much open, precautions are being taken.
To date, a handful of international schools in Thailand have been closed on a case-by-case basis where a member of the school is suspected or confirmed of having the virus. As this number has slowly risen over the past few weeks, schools have been getting prepared for countrywide closures.
During the closure period, campuses will be deep-cleaned, and any staff and students who had close, sustained contact with an infected person will be issued a 14-day self-quarantine.
Over the next two weeks all schools will need to deliver online learning to their entire student body, something many are well-prepared for. Schools such as Bangkok International Preparatory School (Sukhumvit 77) say that they have "used the past three weeks to pilot our online learning with selected students who have been self-quarantined".
Simon Aves, director or ICT at Shrewsbury International School, Bangkok (which remains open) says: "The recent concerns surrounding Covid-19, and the requirement for some students to stay at home following travel to “at risk” countries, has brought Shrewsbury’s online learning plans into action.
“Our virtual learning environments are well established. Firefly and Google Classroom are already used on a day-to-day basis across the school, allowing teachers to share lesson resources, assessment materials and home-learning activities.”
Read more: How Are Hong Kong Schools Coping With Closure?
Prior to the school closures, all students and staff have been subject to a 14-day self-quarantine if they have visited any of Thailand’s list of At-Risk Countries within the past 14 days. These include Japan, Norway, the US, France, Germany, Spain, Sweden, Switzerland, the Netherlands, Denmark and the UK.
They also had to self-quarantine for 14 days if they have visited or been in contact with immediate family members who have visited any of Thailand's Disease Infected Countries list; this includes China, Hong Kong, Macau, Iran, Italy and South Korea.