The council has three months to review its procedures

Two teachers and 25 children from Crookhill Primary in Gateshead were taken to hospital on 14 November.

Eight of the children were found to have raised levels of carbon monoxide and were treated with oxygen.

The Health and Safety Executive (HSE) said Gateshead council should overhaul its arrangements for the maintenance of gas-fired appliances.

Tests have already been carried out at schools with similar heating systems to Crookhill, and no problems were identified, according to the HSE.

Maureen Kesteven, strategic director of legal and corporate services at Gateshead council, said: "The health and safety of pupils and staff is our prime concern and we have taken precautionary measures to conduct a programme of inspections and tests in schools and other council buildings with similar heating installations.

"No significant concerns have been identified to date. We are also carrying out a full review of our arrangements for the maintenance of gas-fired appliances."

Crookhill has since re-opened, with a temporary heating system and carbon monoxide detectors in place.