Most students were allowed to return to some elementary schools in England on Monday as lockdown measures eased, but many parents have decided to keep their children home, concerned that the risks posed by the coronavirus remain too high.

Schools have remained open throughout the lockdown for thousands of vulnerable students and the children of essential workers, but only a fraction of those eligible attended. Only half of those eligible to return on Monday were expected to attend, according to the National Foundation for Educational Research, an independent research group.

Jeanelle de Gruchy, the president of the Association of Directors of Public Health, said in a statement that Britain, which is experiencing one of the world’s highest death rates from the coronavirus, needed to balance the push to ease restrictions with the risk of causing a resurgence of infections.

“We are at a critical moment,” she said, adding that public health experts “are increasingly concerned that the government is misjudging this balancing act and lifting too many restrictions, too quickly.”

The success in reopening schools has varied, as each country has navigated the delicate balance. Germany began allowing students back last month with classroom sizes cut by half and some schools testing for the coronavirus.

France reopened preschools and primary schools last week, but 70 schools were forced to close after new infections were reported, the ministry of education said. In South Korea, schools reopened in late May with new restrictions like plexiglass barriers between desks and temperature checks. But hundreds were closed within days.

The UK government’s gradual restart of public life, which on Monday also included the opening of retail stores and allowing groups of up to six people to meet outdoors, has faced criticism. John Edmunds, a senior scientific adviser, said that relaxing lockdown measures was a “political decision” and that “many scientists would wait,” the BBC reported.

Lunch in a glasshouse: Customers seated in small glasshouses enjoy lunch at the Mediamatic restaurant in Amsterdam on Monday. (AP photo)