A 30-year-old man has been arrested on suspicion of attempted murder after a member of hospital staff was stabbed.

The Royal Sussex County Hospital in Brighton was put in lockdown following the incident on Sunday morning with searches of the premises concluded in the early afternoon.

The victim was initially said to be in a “life-threatening” condition but Sussex Police later said that was no longer the case.

A force spokesman said the incident was not being treated as a terrorist attack and no-one else had been hurt.

He added that a 30-year-old man had been arrested on suspicion of attempted murder.

The police spokesman said: “At 8.42am on Sunday, police were called to the Royal Sussex County Hospital in Brighton after a report that a member of staff had sustained a stab wound.

“The hospital site was quickly secured while officers have been working with security staff to confirm that nobody else has been injured, and that staff and patients are safe.

“Following immediate police searches and inquiries, a 30-year-old man was arrested in nearby Wilson Avenue at 9.40am on suspicion of attempted murder, and is currently in custody for interview and further inquiries.

“This apparently isolated and unexplained incident is not being treated as terrorism at this time and there is currently nothing to suggest that any other person has been involved or that anyone else is at risk.”

He added: “The injuries to the victim, who is 56, are not assessed as life-threatening. His family have been informed.

“The precautionary search of the hospital is now concluding and we thank all staff and patients for their patience and co-operation.”

Brighton and Sussex University Hospitals NHS Trust posted on Twitter: “An incident took place at the Royal Sussex County Hospital this morning in which one member of staff was injured. The staff member is in a safe and stable state, and is being cared for in the hospital.”

It added: “The police and hospital security staff have secured the site and currently, the public are not being allowed into the hospital whilst a search of the premises is carried out.

“The police have arrested one person in relation to the incident. Further updates will follow.”

UNISON Central Sussex Hospitals branch secretary Mark Sargent said: “Our thoughts are with our injured colleague and his family.

“NHS workers who’ve been keeping people safe during the pandemic shouldn’t have to face violence when they’re doing their jobs. Security staff and police deserve huge credit for their timely and decisive action.”

Twitter user Dan Dawson posted: “The victim is a member of staff. One of the hardworking cleaners. Disgusting to think they’ve been working so hard fighting the virus only to be attacked. Thoughts with the… family.”

Health Secretary Matt Hancock tweeted: “My thoughts go out to the staff member at the Royal Sussex County Hospital who was injured this morning. I will not accept violence against NHS staff – we will bring the full force of the law to bear on anyone who attacks public servants in their line of duty.”