Armed police were spotted in Winckley Square triggering worry for nearby businesses and residents.
AdvertisementAround 4.30pm on Thursday (27 October) the SWAT teams were seen stopping a vehicle.
A police car with armed officers was also in operation.
It is understood the incident was a training exercise.
Blog Preston asked Lancashire Police for more information and confirmation it was a training incident, but no information was provided.
Read more: College House owners forced to repair Winckley Square building
Behind the armed officers the ongoing work in Winckley Square can be seen, as part of a major restoration project.