Dozens of firefighters have been tackling a fire at a store in Blackwood High Street.
The service says it started at around 2 o'clock this morning
There are no reports of injuries.
Firefighters were drafted in from Cefn Forest, Abercarn, Cardiff, Cwmbran and Merthyr.
Local residents are being asked to keep windows and doors shut.
The street's closed but other roads in the area are also likely to be affected.
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Breezy overnight. It will become fairly cloudy as the night progresses.
It should turn cloudier through the early hours with some patchy drizzle and some hill fog too.
It will be a breezy day with variable amounts of cloud and some bright or sunny spells.