The air ambulance landed in Bognor last night, according to reports.
The life-saving helicopter flew over and landed in the town, reports on social media say.
It is not known if these sightings are connected to separate reports of a police incident in High Street.
Sussex Police declined to provide any information when approached by the Observer this morning.
The air ambulance charity has been approached for comment.
Did you see what happened?
If it is safe to do so, email email@example.com