Firefighters are currently battling a serious fire in Southover High Street, Lewes.
Crews from Lewes, Newhaven, Roedean and Burgess Hill have been sent to the blaze in a residential property after receiving a call at about 4.20pm.
East Sussex Fire and Rescue Service said they are currently tackling a roof fire there.
All people are accounted for, the service said.
There is severe congestion reported in the town centre.