It was gathered that the fire started at about 2am, when only a few of the staff were present.
Several goods worth billions of naira were said to have been affected by the fire. The supermarket houses several sections, including a boutique, bakery, food and beverages as well as home appliances.
The mall was also said to have over 50 employees and had recently undergone a major renovation.
When our correspondent got to the scene of the incident at about 9am, officials of the state fire service were seen battling to put off the fire.
Although it was learnt that firemen from the Nigerian Airforce and the University of Benin visited the scene, the inferno was extinguished at about 11:30am.
Efforts to speak with the management of the mall were not successful as the manager declined comment, as sympathisers thronged the premises of the mall.
Governor Godwin Obaseki, who was among the early callers, was at the scene to inspect the level of damage.
A customer, who identified herself as Mrs. Grace, expressed displeasure over what she described as a poor response in extinguishing the fire.
She said, “I came to shop. But I am shocked because from what Hallmark has, this (destroyed property) is running into billions. How can a place like Hallmark burn down like this?”