Education authorities in the United Kingdom has told at least 104 schools and colleges to shut their buildings that are prone to collapse.

The education ministry said Thursday that affected schools buildings are those made with Reinforced Autoclaved Aerated Concrete which was widely used for school and college constructions from the 1950s to the mid-1990s.

RAAC poses collapse risk over time and schools were warned about this and told to implement mitigations as early as 2018, according to the ministry.

In its new guidance, the ministry asked that affected buildings be vacated and to either fully or partially relocate to alternative accommodation.

The announcement comes as millions of pupils in England are returning to school after the lengthy summer holidays.

"Nothing is more important than making sure children and staff are safe in schools and colleges, which is why we are acting on new evidence about RAAC now, ahead of the start of term," Education Secretary Gillian Keegan said.

Education officials, public-sector unions and opposition parties hit out at the government.

Unison union's head of education Mike Short said it "squandered valuable months hiding this crisis when they should have been fixing dangerous school buildings."

WITH AFP