Police in riot gear descended on a Dundee multi-storey on Thursday night after reports of concern for a person.
A man, 40, was later arrested and taken to Ninewells Hospital for treatment.
The nature of his condition is not known.
At 9pm around six police vehicles with armed officers were seen to arrive outside the multi-storey in the Hilltown.
Police were still on the scene well after midnight.
Man taken to hospital
A Police Scotland spokesperson said: “Around 8.55pm on Thursday we were called to a report of a concern for person in the Hilltown Court area of Dundee.
“Officers attended and a 40-year-old man was arrested in connection with the incident, and was later taken to Ninewells Hospital for treatment.”
One resident said: “I was looking out my window just before I went to bed and saw several police cars and vans pull up.
“Loads of police got out and started surrounding Hilltown Court.
“There were police in riot gear.
“They went to both the main entrances and around midnight police in riot gear went into the building.”
Police at both entrances
Another said: “I became aware of the police presence at around 10.30pm.
“There were six police units in attendance and there were officers around the perimeter of Hilltown Court.
“There were police on both entrances of the ground floor.
“Officers in riot gear entered the multi shortly before midnight.””
Another added: “The place was crawling with police when I was walking home just after 11pm.
“They were parked along Hilltown Terrace at the first multi. I could see they were positioned on the ground floor of the building.”