A fire has ripped through the building complex containing Adelaide's historic Oxford Hotel.
The hotel has been closed since September, and authorities say the fire occurred in an adjoining accommodation facility.
What's next:
Police are treating the fire as suspicious and are calling on anyone with information to contact Crime Stoppers.
Police say a large fire that caused significant damage to the building complex that houses Adelaide's historic Oxford Hotel may have been deliberately lit.
Firefighters were called to the building, on the corner of Tynte and O'Connell streets in North Adelaide, around 7am.
The Metropolitan Fire Service (MFS) said the fire started in an accommodation area adjoining the historic pub.
"The MFS managed to contain the fire to the accommodation facility," an MFS spokesperson said.
No injuries have been reported, but police say the fire is being treated as suspicious.
"There is significant damage to the building," a police spokesperson said.
"Fire cause investigators and Eastern District detectives are at the scene to determine the cause of the fire, however, police are treating this fire as suspicious."
Authorities issued a smoke warning this morning asking people in the area to keep windows and doors closed and police closed O'Connell Street between Tynte Street and Gover Street and diverted traffic. Roads have since reopened.
Adelaide's historic Oxford Hotel on fire. (Supplied: Lorenzo Krstic)
It took about nine fire crews with some 50 firefighters around 45 minutes to control the blaze.
Some firefighters were seen climbing to the upper level of the building in an attempt to put out the fire.
Police have appealed to anyone with information, or CCTV or dashcam footage, that could assist the investigation to contact Crime Stoppers.
Firefighters at this morning's Oxford Hotel fire. (ABC News: Shannon Pearce )
Large plumes of smoke could be seen pouring from the building when crews doused the back half of the complex with water.
MFS Incident Controller Chris Castle said the fire was in the building's rear accommodation and crews had to attack the blaze internally.
“Firefighters responded quickly. We had three sectors: front, back and aerial,” he said.
About 50 firefighters were called to the scene in North Adelaide. (ABC News: Shannon Pearce)
Mr Castle said there were reports of people squatting but nobody was found when authorities arrived.
Fire attracts small crowd
The hotel closed last year, but there were reports of potential squatters occupying the building. (ABC News: Shannon Pearce )
The fire stopped early morning walkers in their tracks with one onlooker saying it would be "heartbreaking" to lose the hotel.
"It's a very historic building," Lucy said.
She recalled going to the pub for meals before it had shut.
An Instagram post from last September had invited patrons to a closing down party.