At least one person is reported to have been stabbed during three “serious incidents” in East Ayrshire.
University Hospital Crosshouse in Kilmarnock was placed in lockdown on Thursday evening, with ambulances diverted to University Hospital Ayr as police dealt with the unfolding events.
The three-hour lockdown was lifted shortly before 23:00.
The PA news agency said it understood at least one person was stabbed.
There was no official confirmation from Police Scotland.
Officers were called to the first incident at the Crosshouse site at about 19:45 on Thursday.
They believe another in the centre of Kilmarnock about 20 minutes later and a serious crash on the A76 may be linked.
In a statement on Twitter Police Scotland said there was no cause for concern for the wider community.
It added that inquiries were at an early stage and that the areas involved have been cordoned off.
The second incident was on Portland Street, which is about two miles from the hospital, at about 20:05.
Officers were called to the crash on the A76, on the outskirts of the town, at about 20:30.
Local residents reported hearing sirens and a helicopter overhead shortly before 20:30.
On Friday morning, the hospital’s A&E department and main entrance were open and running as normal while two police vans full of officers remained outside with police tape around part of the car park.
Dr Crawford McGuffie, the medical director of NHS Ayrshire and Arran, said police had confirmed the risk to patients, staff and visitors to the hospital was minimal.
He added: “There remains a large police presence on the grounds of the hospital.
“We would like to reassure anyone coming to the hospital, in particular to any patients or staff coming on shift, that Police Scotland have confirmed it is safe to do so.
“However, if you are worried, please speak to the onsite Police Scotland officers.”
First Minister Nicola Sturgeon described the incidents as very serious.
She added: “My thoughts are with those involved in these very serious incidents… Please help police do their job by following the advice to stay away from the areas affected.”
Health Secretary Jeane Freeman, who is also an Ayrshire MSP, commented on BBC’s Good Morning Scotland about the events of Thursday night.
She said: “They are very worrying and as I said last night my thoughts are with the family and friends of all those affected and with our colleagues in the NHS and Police Scotland and I want to thank them again for responding to these incidents in the professional, swift and caring manner that I know they will have done.”