The device at a the Toymaster store in Cookstown partially detonated.

And cops have urged businesses to be vigilant on a daily basis, adding that " crude devices can take human life".

Army technical officers found the device hidden in a fast food container at the Dungannon Road store on Friday night.

The shop was evacuated before the device set fire to some surrounding stock and burnt itself out.

The search followed a phone call to a media organisation warning that incendiary devices had been left at two businesses in Cookstown.

A supermarket in the town was also evacuated and a number of other premises were searched but no other devices found.

It's understood shopkeepers in Cookstown had been on alert following a warning from the police on Thursday.

A PSNI spokesman said "investigations into the exact nature of the object are continuing".

There has been speculation that dissident republican terrorists may have been responsible, but the police refused to be drawn.

In a statement urging business owners to be vigilant on a daily basis, the PSNI warned: "Crude devices have the potential to destroy property and take human life.

"Devices can be left in garments, soft furnishings, and upholstery, anywhere that can catch fire easily or concealed within other boxes or packages.

"Business owners and staff must be observant and look out for anything suspicious. If something looks out of place, or even just raises concern, contact the local police.

"Members of staff should not touch or move any suspicious looking objects, but rather contact police immediately."

Crime Prevention Officers are available to give individual advice to any business throughout Northern Ireland and can be contacted at local police stations on 0845 600 8000.