South Yorkshire Police said ‘a number of young people’ were involved in the disturbance yesterday.
The force said there were no injuries reported and inquiries into the incident remain ongoing.
But an eyewitness, who described the incident as a “riot”, said “screaming shoppers” fled when the violence broke out.
The witness, who was sat in The Steel Foundry pub owned by the Wetherspoons chain at the time of the incident, said they saw youths “battering each other,” smashing a chair and “punching and kicking” each other.
The shocked witness said “shoppers were running, screaming, away from the fighting".
It is reported that a number of people filmed the violence on their phones as it unfolded.
“The youths were just running in and out and battling at will. It was like a riot,” the witness said.
“It was hellish. A lot of shoppers were absolutely terrified and either fled or hid.”
South Yorkshire Police said: “Police were called at 7.18pm yesterday evening to reports of an altercation in the Oasis Dining Quarter at Meadowhall.
“Officers attended and it is believed the altercation took place between a number of young people.
“No injuries were reported. Inquiries are ongoing.”
The Oasis dining quarter boasts a number of popular restaurants as well as fast food outlets.
There is also a large communal dining area.
A spokesperson for Meadowhall said: “The safety of our customers and colleagues is our number one priority. Our team responded quickly to an isolated incident yesterday evening and we are supporting the police with their investigations.”