Crews from Lancashire Fire & Rescue Service battled a fire at the Grill and Grain at the Boatyard.
The canalside pub and restaurant is located on Bolton Road in Ripley Green.
Six fire crews fought the blaze using hose reels, according to reports.
The premises were evacuated safely and everyone has been accounted for.
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A statement from Thwaites, issued during the fire, said: “We are currently working with Lancashire Fire & Rescue Service after a fire started at Grill & Grain at the Boatyard in Riley Green at around 11.45am.
“As you can appreciate, our priority is the safety of our guests and staff, and as soon as the fire was discovered everyone was immediately evacuated from the building.
“The fire service is still at the scene so we can’t comment further at this time.”
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The restaurant reopened in November 2016 following an extensive refurb.
We’ll provide more information as it becomes available.