A major incident has been declared at Lincoln County Hospital after fire broke out in the the early hours of this morning.
The blaze started at around 3am in the interventional radiology department, which hospital bosses say was "gutted".
No one was injured, but smoke damage also meant the emergency department and urgent treatment centre had to be closed, with patients being transferred to other departments.
A MRI and CT scanner were damaged. It is not yet known what caused the fire.
The A and E and urgent treatment centre are closed to new patients until further notice, with some outpatient appointments cancelled.
Chief executive Andrew Morgan speaks to ITV News
Chief executive Andrew Morgan said equipment needed to be tested to make sure it was safe and the affected departments may not reopen until Wednesday.
He said: "Covid is still with us, we have a number of Covid inpatients. It's a busy time of the year. Nobody ever wants anything like this to happen but this is why we have emergency plans, that's why we practice some of these things."
In an earlier statement, the hospital said: "Patients and staff were evacuated from the emergency department in the early hours of this morning.
"Nobody was injured and patients are now being cared for in other areas of the hospital.
"The fire has been extinguished, but our emergency department remains closed at this time."
Anyone needing non-life threatening urgent or emergency care is being advised to call 111, or 999 if the situation is life threatening.
Patients who were due to attend a scanning appointment are also being asked to stay away. The hospital says all affected patients will be contacted.
Six fire crews attended the blaze and used breathing apparatus and a thermal imaging camera.
The fire service said: "Lincolnshire Fire and Rescue were called out at around 3am this morning to a fire at Lincoln County Hospital.
"Six crews attended to extinguish the fire using a hose reel jet, breathing apparatus, a portable pump to ventilate and a thermal imaging camera.
"The fire has caused severe damage to the entirety of a treatment room and its contents. There was smoke damage to the adjoining corridor.
"All crews have now left the scene and the cause is currently unknown until the fire investigation is complete later this morning."