A critical incident has been declared at a Norfolk hospital after fresh concerns emerged over its roof.

A "small number" of patients have been moved out of the critical care unit at the Queen Elizabeth Hospital (QEH) in King's Lynn, a spokesman said.

Bends have been previously been found in some of the concrete planks used to build the structure at the QEH in the late 1970s.

It comes three months after two wards had to be temporarily closed to have parts of the roof supported with steel props.

A hospital spokesman said: “While we carry out essential maintenance work on our critical care unit, we have temporarily moved a small number of patients. We continue to have critical care capacity available while this work is under way and we are treating patients safely, as normal.”

The QEH says the work is part of its "rolling programme of estate management" and follows a routine roof inspection.

The hospital, which was originally intended to have a working life of 30 years, celebrated its 40th anniversary last year.

Similar planks have failed in public buildings whose roofs were constructed from them elsewhere in the country.

The hospital's risk register, which was reviewed by its governing board on March 2, states: "There is a direct risk to life and safety of patients, visitors and staff due to the potential of catastrophic failure of the roof structure due to structural deficiencies."

In October, hospital bosses said it would cost £554m to maintain the roof over the next 10 years. The sum is almost as much as the cost of building a new hospital.

The QEH is one of 16 hospitals competing for a share of a government funding pot, from which eight will be chosen to deliver a new hospital by 2030.

It missed out in an earlier funding round announced by prime minister Boris Johnson in October, in which the James Paget, in Gorleston, and West Suffolk, in Bury St Edmunds, hospitals were both allocated funds to build new hospitals, along with a new cancer hospital at Addenbrooke's, in Cambridge.