Armed police were deployed after reports men had been seen in South Shields town centre with a gun.
The officers located a car at Asda in Coronation Street following a search of the area.
The incident happened at 8.10pm yesterday, when Northumbria Police received reports of a suspicious vehicle travelling on Ocean Road.
The report stated that the men in the vehicle, a navy blue Vauxhall Astra, were seen with what appeared to be a handgun.
Armed officers were deployed and the car was located in the car park at Asda.
A cordon was put in place around the underground car park and police carried out a search of the vehicle and the occupants.
A spokesman for the force said the report was made in good faith, however police would like to reassure members of the public that no weapons were found during the search.
People in the store were asked to stay away from the underground car park to allow officers to carry out a safe search.
Chief Inspector Lee Gosling said: "We take reports involving firearms incredibly seriously and will always respond proportionately to ensure the safety of our communities, public safety is our utmost priority.
"On this occasion it would appear the report was made in good faith and a firearm was not found during our searches of the vehicle and the occupants.
"There were reports on social media stating that an explosive device had been found but I can categorically say this was not the case and no such items were discovered or ever believed to be involved.
"There was some slight disruption around the car park in Asda last night and I would like to thank members of the public who were affected and staff at the store for their understanding and co-operation to allow us to deal with the incident safely and securely."
The force said reports on social media had stated an explosive device was present at the scene.
A spokesman added: "This is false, no such item was discovered or was ever believed to be involved."