Norfolk's biggest hospital was forced to declare a black alert as its emergency department experienced the busiest day in its history.

The Norfolk and Norwich University Hospital (N&N) has been at the heightened status of 'black alert' since a spike in patients at A&E on Sunday – including more than 130 ambulance arrivals.

Today, the hospital said it de-escalated to a red-alert.

Black alert means the hospital will look at emergency steps to free up capacity including postponing surgeries and opening day-only units overnight.

Richard Parker, chief operating officer of the N&N, said: 'We can confirm that we declared black alert on Sunday.

'This heightened status is part of our established, planned response to deal with spikes in activity.

'The alert status is designed to elicit an additional response internally and from partner organisations in the system to quickly remove blocks or delays at times of these activity spikes.

'Sunday was our busiest day in the emergency department on record with 385 patients in total, with 140 patients booking in between 10am and 2pm, and 132 ambulances arriving on Sunday, with another 149 on Monday.

'As part of the black alert, we review the situation three times a day looking at our planned activity, specifically to make sure that the most urgent or sick patients are always treated.

'On occasion we have had to postpone routine surgery but wherever possible we attempt to avoid this.

'Our staff have been working very hard, to support patients while we continue to experience a high level of emergency demand.'

It is the latest hospital in the region to declare black alert, after the Queen Elizabeth Hospital in King's Lynn last month.

A&E departments often experience greater pressure through the winter months. Last December, five hospitals in the east of England declared a black alert on the same day.

It comes amid leadership changes at the hospital. The chief executive Anna Dugdale and director of resources Julie Cave have both departed in recent months.

•Health regulator the CQC is asking people for their views of the N&N.