South Korea has been forced to close hundreds of schools just days after they re-opened following a new spike in virus cases.
Thousands of students had earlier on Wednesday returned to school as the country began easing virus restrictions.
But just a day later, 79 new cases were recorded, the highest daily figure in two months.
A total of 251 schools in Bucheon have now been forced to close. A report by the Korea Times, quoting the Ministry of Education, says a further 117 schools in the capital Seoul have also postponed their re-opening.
It comes as Sheffield City Council advised schools not to open to more pupils from Monday, citing fears that the NHS Test and Trace system will not be “robust enough” to be in place by next week.
The decision comes after Prime Minister Boris Johnson announced that the Government’s five key tests required for the easing of the lockdown have been met – and schools can admit more pupils from next week.
Primary schools across England will reopen to children in Reception, Year 1 and Year 6 from June 1.
But the local authority in South Yorkshire said it does “not yet feel assured that it is the right time” to admit more children and it is advising schools and nurseries “to delay increasing numbers” until June 15.
Councillor Abtisam Mohamed, cabinet member for education and skills, said: “We have been advised by the Sheffield director of public health, Greg Fell, who has reviewed the local position, and he does not feel assured that the recently announced Test and Trace programme will be sufficiently well-established and robust enough to be in place for June 1.
“He has advised that the Test and Trace system should be in place and working effectively for 14 days before schools and nurseries begin increasing their numbers.”
Mr Mohamed went on: “We do not yet feel assured that it is the right time and are advising our schools and nurseries to delay increasing numbers until June 15.
“For maintained schools, where the council is the employer, we are instructing schools not to increase the number of children attending more widely.
“For all other schools, academies, and nurseries in Sheffield, we are strongly advising that they also delay their wider reopening to June 15.”