School buildings in parts of Devon are being checked for a type of concrete which has forced some schools across the country to close amid safety fears.

The government says 156 school buildings nationwide have been built using reinforced autoclaved aerated concrete, known as RAAC, and 52 risk sudden collapse. Action has been taken to make them safe, in some cases by propping up the concrete.

The Department for Education has so far declined to say which schools are affected, but believes the remaining 104 were safe for children to be in.

However, the government has now discovered cases where low-risk RAAC turned out to be unsafe, and in one school a beam collapsed.

Dozens may have to close, and the BBC says hundreds more schools are yet to conclude whether or not they have RAAC. It reports a June report by the National Audit Office which says 572 schools have been identified where RAAC might be present. Engineers have been carrying out surveys to work out where the problems are.

Finding out which schools are affected is complicated by the fact that many schools or the trusts that run them are responsible for their buildings, rather than local authorities.

A Devon County Council spokesperson said: "We have worked with the Department for Education on this process and don't believe that any schools for which we are responsible have been affected, nor have we received any feedback from other responsible bodies regarding their buildings."

The government has still not published the list of schools affected, but it says it will.