The Police Service of Northern Ireland has begun an investigation into the latest of a series of fires at business premises in the North.
The latest suspected firebomb attack saw a blaze break out in the stationery section of the Poundstretcher shop in Newtownabbey, on the outskirts of north Belfast, shortly before midnight.
As fire crews arrived to fight the blaze, it threatened to spread to nearby electrical premises.
Although the cause of the fire has not yet been established, keyholders of stores in the vicinity were urged by police to return and check their premises for incendiary devices.
Yesterday it was confirmed a blaze at the B&Q superstore at the Sprucefield retail park in Lisburn, Co Antrim, was caused by an incendiary bomb. It took more than 100 firefighters several hours to get the blaze, which started in the rugs department, under control.
The rest of the premises, which opened earlier this year, was damaged by smoke and water from the sprinkler system.
The PSNI called those responsible for the arson attack "mindless criminals".
Last night, a partially exploded incendiary bomb was discovered by staff in a Homebase DIY store in Derry. Only minor damage was caused to the shop on the Crescent Link retail park.
Elsewhere, a fire that caused £100,000 sterling damage to a carpet store at another retail park in Derry on Sunday morning is also believed to be the result of arson, although forensic tests have so far proved inconclusive.
Another device was found in a sports shop in Newry, Co Down, on Saturday night.
PA