The Education Ministry and schools are preparing for schools to reopen nationally after the ministry's surveys found 60-70% of students are not ready to use television as the main channel for their studies.

Education Minister Nataphol Teepsuwan said the ministry changed its previous plan from airing lessons via television for long distance learning as part of measures to prevent the spread of Covid-19.

However, the survey found most students consume media via their smartphones which can be costly.

Measures following a recommendation by the Ministry of Public Health will be taken, including a limit of 20 to 25 students per classroom.

Mr Nataphol rebutted a report there would be regulations on which style of face masks students would be allowed to use, saying sanitary and protection measures were the focus.

His comment came after criticism in social media towards a picture of a bulletin board at a school which showed plain-coloured face masks as examples of masks which students would be allowed to use once the school was reopened.

Meanwhile, Bangkok deputy governor Sopon Pisuttiwong said the Bangkok Metropolitan Administration (BMA) is studying countries such as Denmark and France, where schools have opened, to find suitable measures for Thai schools to reopen from July 1.

The current thinking is that schools under the BMA would be required to keep students, as well as their desks, 1-2 metres apart, he said.

"Students will be allowed to play only in small groups and they must wash their hands every hour or more often," he said.

"Desks, doorknobs, and playgrounds as [infected-prone] risky areas will be cleaned twice a day.

"Students will not be allowed to eat together. A sick student must go home straight away and enter self-quarantine," he said.