A man has been taken to hospital with life-threatening injuries following a “medical incident” at a shopping centre.
Sussex Police said it happened at the County Mall, in Crawley, at about 13:45 BST on Sunday.
An increased police presence was expected in the area, although the incident posed no threat to the public.
The shopping centre declined to comment.
South East Coast Ambulance Service and the Air Ambulance Charity Kent Surrey Sussex have been contacted for more information.