Counter-terror police have arrested a 27-year-old man after he was allegedly seen with a firearm and a suspicious package at a hospital's maternity wing.
And in an update late this evening, Counter Terrorism Policing North East said the man has been re-arrested on suspicion of being concerned in the commission, preparation or instigation of acts of terrorism.
Counter Terrorism Policing (CTP) North East said wards on the Gledhow wing of St James's Hospital in Leeds were evacuated after the suspect was detained at around 5am on Friday.
Tonight, the hospital was open again and searches of a vehicle had concluded there - but continued to be carried out in Leeds.
Detective Chief Superintendent Jim Dunkerley Head of Counter Terrorism Policing North East, said: “This is being treated as an isolated incident. There is no evidence to suggest any heightened or ongoing risk to the public.
Two New York cops stabbed during celebrations in Times Square“Nevertheless, the UK threat level remains at Substantial and we would always encourage the public to be vigilant and to report any suspicious activity or behaviour to police in confidence on 0800 789 321 or at gov.uk/ACT.”
Army specialists and a bomb disposal unit attended the scene and a cordon was put in place as a precautionary measure, but it was later reduced to facilitate greater access to the hospital.
Police said extensive inquiries are under way to establish the full circumstances of the incident and any potential motivation.
The wing is home to the majority of the hospital's maternity services, as well as some respiratory and bereavement services.
CTP North East, which is leading the investigation, said searches of a car and a number of premises are ongoing - and the suspect, from Leeds, remains in custody for questioning.
In a statement, CTP North East said: "Extensive enquiries are underway to establish the full circumstances of the incident and any potential motivation.
"This is being treated as an isolated incident at this time. We ask that people continue to use alternative entrances to the hospital. The Emergency Department at St James’s remains open, and patients are asked to attend outpatient appointments as normal unless contacted otherwise."
Police said it is being treated as an isolated incident and there is not believed to be any ongoing risk to public safety.
Pictures from the scene show a heavy presence of soldiers and emergency services alongside the cordon, with firefighters seen around midday and appeared to be readying themselves..
Visiting has been suspended but patients are being asked to attend their appointments at the hospital as normal unless contacted and A&E remains open.
At least nine killed after New Year's Day stampede at shopping centreSuperintendent Dan Wood, of West Yorkshire Police, said: "This incident was brought to a safe conclusion by the work of the emergency services, and a man has been arrested in connection with it and remains in custody.
"We are continuing to liaise with our counter terrorism colleagues as they progress their investigation.
"We recognise that an incident of this nature will cause understandable public concern and we are linking with our partner agencies and key community representatives to reassure them and keep them informed."
Mr Steve Bush, Medical Director (Operations), at Leeds Teaching Hospitals NHS Trust, confirmed around 4.47pm that the incident has been "stood down" but a cordon remains in place while police enquiries continue.
He said: "The critical incident at St James’s Hospital has been stood down. Police and specialist services remain on site as the investigation is ongoing. We'd like to thank our patients and the public for their patience and understanding during this matter.
"We want to wholeheartedly thank our staff and the Emergency Services for their dedication and commitment to ensure we have been able to keep everyone safe. Patients who were evacuated are being moved back to their wards.
"It may be some time before we are back to business as usual in these areas, so please bear with us."
He added: "Our patient helpline has been stood down and visiting has resumed as normal across Gledhow wing and Lincoln wing.
"Unfortunately some patient appointments were cancelled as a result of today's incident and we would like to apologise for the inconvenience caused - these will be rearranged as soon as possible.
"A cordon remains in place outside Gledhow wing whilst the police investigation continues, but has now been reduced to allow greater access to the hospital.
"The front entrance to Gledhow wing will remain closed for the rest of the day so please continue to use alternative entrances through Alma Street (Bexley wing entrance) or Gledhow Road."