Part of Market St has been closed to traffic after a major fire at The Manhattan Bar in the early hours of Sunday morning.
The fire caused substantial damage to the building and the motorway/Portadown bound direction of Market St has been shut due to the risk of the building collapsing.
There is restricted pedestrian access on the street adjacent to the damaged premises.
A Roads Service spokesperson added: “A diversion has been put in place via Millennium Way. The road will be closed until the building has been structurally assessed and made safe.”
Police and fire crews attended after it was reported at 5.20am.
Firefighters brought the blaze under control after several hours.
No one was inside at the time and the cause of the fire is being investigated.
Edward Carroll, NIFRS group commander, said that at the height of the incident, five appliances, two aerial appliances and a command support unit were involved in the operation.
He said extensive damage to the building had caused two floors to collapse and the roof to cave in.
“It was a difficult fire to bring under control and I have to praise the valiant actions of crews who actually brought the fire under control at 10.45 this morning,” he said yesterday.