The Danish government, which plans to ban social media use among students under the age of 15, also wants to ban mobile phones in primary and lower secondary schools, the country’s prime minister announced on Thursday.

“This government is proposing a complete ban on mobile phones,” Mette Frederiksen said during a press conference.

The ban would apply to students from the first year of primary school through the end of lower secondary school, both inside classrooms and in school playgrounds, she clarified.

The announcement comes as the performance of young Danes has declined sharply in the international PISA rankings. Published every three years by the Organisation for Economic Co-operation and Development (OECD), PISA has become a global benchmark for evaluating education systems.

With a score of 478, Denmark ranks slightly below the European average of 482.

“Results in reading, mathematics and science are the worst ever recorded,” Education Minister Magnus Heunicke said following the release of the study’s results.

The Danish prime minister said she was convinced that the results were closely linked to the fact that Denmark has “one of the most digitally connected generations of children.”

“We adults have allowed children and young people to spend far too many hours a day in front of a screen,” she added.