They would be followed by younger secondary and older primary school pupils, who could resume classes in June by the earliest.

But most universities would continue to conduct online lessons until the current semester ended in May, while alternative forms of assessments such as online exams would be carried out.

Hong Kong has chalked up 15 consecutive days without any new local infections, while one imported case of Covid-19 was reported on Monday. The infection total remained at 1,040, with four related deaths.

The Education Bureau was expected to announce detailed arrangements for class resumptions by Tuesday at the earliest. It previously said it would make the decision about three weeks before classes resume, so schools have time to prepare.

It was understood that school heads met education officials on Monday, following a meeting last week to discuss details on a return to normal.

Two sources said principals were told to place desks about one metre from each other in classrooms, based on advice from health officials, while classes would resume on a half-day basis, avoiding the need for students to eat lunch in school, and the attendant risk of infection.

The sources added that, during recesses, pupils would be required to stay at least a metre apart, while PE lessons may take place but students would wear masks and keep their distance from each other.

A preliminary set of guidelines had been discussed as officials were still working on the final details.

A secondary school principal told the Post that spacing each desk out by a metre would be difficult in practice.

“Classes usually have at least 20 to 30 students. By placing each desk one metre from each other, each classroom would only be able to accommodate 15 to 20 students. What about the rest of the students?” the principal said, adding that placing students in single rows instead of double-desks would reduce some of the risks, given all students wear masks in class.

Health officials last week updated Covid-19 guidelines for schools, saying all students must have their temperature checked before entering campus, while any who have a fever or other respiratory symptoms should be asked to leave and see a doctor immediately.

The government earlier exempted more than 25,000 cross-border primary and secondary school students – Hongkongers living in mainland China who cross the border every day to go to school – from having to undergo 14-day quarantine when they enter the city.

Chu Wai-lam, principal of Fung Kai No 1 Primary School in border town Sheung Shui, more than half of whose 1,100 students are cross-border pupils, said he believed the health risks would remain low as the number of cases in Hong Kong and neighbouring Shenzhen had lowered recently.

“But of course, if infected cases in Hong Kong or Shenzhen suddenly surge, this exemption should be considered for cancellation, in order to lower the health risks,” he said.

Chu said his campus would undergo thorough disinfection again in mid-May, while the school had also installed an infrared screening machine to check students’ temperature upon entering the site.

He said gatherings such as morning assemblies would be broadcast live in classrooms, while most extracurricular activities would be cancelled. Recesses might be extended to allow students to go to washrooms in smaller, separate groups to reduce health risks, he added.

In nearby Macau, classes started to resume in stages from Monday, with 13,000 senior secondary students among the first batch to return, while schools stepped up infection-control measures such as providing more antiseptic materials than usual. Younger secondary students were expected to return to school next Monday.