Cinema bosses have thanked firefighters for their swift response to a blaze which forced the evacuation of more than 200 people.
Tyne and Wear Fire and Rescue Service was called to the Empire Cinema in Lambton Street shortly before 6.30pm on Wednesday evening.
Appliances from Marley Park and Sunderland Central stations dealt with a fire in an electrical cupboard.
Two firefighters using breathing apparatus and CO2 extinguishers tackled the blaze.
Firefighters visited the cinema last night and have given it the all-clear.
The company issued a statement confirming normal service had been resumed: "We are pleased to confirm the fire was successfully contained and all customers and staff safely exited the building."
"The fire was contained within the battery supply room and quickly dealt with by two firefighters from the Tyne and Wear Fire and Rescue Service, who utilised the onsite and fire services’ CO2 extinguishers.
"Staff re-entered the building at 20.30pm on Wednesday following confirmation from the fire service that the site was safe to re-enter.
"Empire Cinemas Sunderland reopened to the public at 19.30pm last night (Thursday 14th September) and the first film commenced at 19.45pm. The cinema has returned to normal operating hours.
"We apologise to all customers who were inconvenienced by the evacuation and to those who held tickets for screenings that were cancelled due to the unforeseen closure. Full refunds are available to those who were affected.
"Any customers who booked tickets online for showings that were subsequently cancelled will receive an automatic refund within five to seven working days. Customers who purchased tickets on-site for screenings which were evacuated or cancelled due to the closure need to return their tickets to the cinema in order for a refund to be processed.
"Empire Cinemas would like to thank the Tyne and Wear Fire Service for their swift response and also Empire Cinema’s customers for their patience and understanding."